Just as an update to this post, I haven’t received anything further from Halo on this topic. Still have the items claimed on Twitch, but only 2/3 do not show up as redeemed on Halo Waypoint.
A bit annoying, for sure…today I submitted a Twitch support ticket just to try, will update with any responses or guidance.
I gave up trying to get my drops. My account is linked, the item is claimed on Twitch, yet I don’t have my HCS Pistol Coating. Asked support, told to submit a new ticket under a different section, did so with an explanation, got an automated response that was of zero help, and then a response saying to once again submit a new ticket under a different section.
Absolute joke, never had problems with Twitch drops like this before in any video game.
They’re gone. light a candle, say a prayer, RIP 
Okay, so I exchanged a few emails with Twitch Support over this situation. BLUF: they didn’t help with anything, and pointed at the game devs to do something about it.
Here’s what they ended up saying to me (had to remove the links to post here)
1st email response
Please refer to our [Drops FAQ] article, which covers key information regarding Drops and answers most questions.
Additionally, we’ve provided a brief list of answers to other common questions below.
1. Why didn’t I receive any drops?
Our new Drops campaigns include both Mission-based and Time-based Drops. To be eligible to receive the Drop rewards in-game, you will need to have your game account [connected] to your Twitch account. Drops are available to claim up to 24 hours after the campaign’s end .
To learn more about how to claim Drops for each type of campaign, please refer to this [FAQ article].
2. Where I can see what drops I’ve received?
Drops you’ve received can be viewed by visiting your [Inventory page].
3. Why can I no longer see some of the drops items that I previously earned on my drops ?
Drops items that were earned through the older legacy Drops service are no longer visible on the Drops inventory page. Don’t worry, this change does not affect the actual Drops items in your connected game account. All items earned from the new Drops service will continue to be visible on the Drops inventory page.
4. I’ve redeemed a drop but the corresponding item isn’t showing up in game!
You can do some initial troubleshooting by checking that the item has shown up on your Drops [Inventory page], that your game account is [connected] to the correct Twitch account, and that you have followed the claiming steps for that campaign type.
You may be experiencing an error message when trying to claim a Drop. This can occur when you claim a Drop in one tab, but are attempting to claim the same Drop in another tab where the Drop is unclaimed. The first Drop should still be claimed successfully and available in your Inventory.
The game developer of the broadcasted game is responsible for fulfilling Drop rewards in-game. Please contact the specific game developer directly for any questions, as Twitch Support do not have the ability to provide or issue drops.
For any other questions or concerns, please feel free to reply and we’ll get back to you as soon as we can.
Thanks for understanding,
Twitch Support
2nd email response
I’m sorry to hear that you are experiencing issues receiving your in-game Drops reward. After taking a look, it appears that the Drop in question has been claimed successfully. Please note that Drops can take around 24 hours to update on the Inventory page.
If you’re having difficulties receiving the in-game item, please contact the game developer for this Drop. Fulfillment of in-game rewards is at the developer’s discretion, and can take time to process even after the Drop is claimed or the campaign has ended. Twitch provides the notifications to users who receive them, but does not have the ability to award in-game items once successfully claimed.
Non-reception of in-game rewards can sometimes be caused by having the wrong game account tied to your Twitch account. Please ensure that you have the right account connected before reaching out to the game developer. You may want to disconnect and reconnect your accounts to prevent issues for future Drops for that game, note that doing so in an incognito browser is often helpful with connection issues.
Thank you for your understanding. If you have any other questions we do have more information about Drops in our help article [here], but feel free to reply if you need anything else and we’ll get back to you as soon as we can.
Best,
Twitch Support
3rd/Final email response
We have reviewed your case thoroughly and can confirm that unfortunately, we cannot provide any additional insight to your request, outside of the solutions we provided in the previous responses. As a result, we will be closing the case in this thread. We apologize for any inconvenience this may have caused you.
If you have another question, please feel free to submit a new ticket under the appropriate category on our [Help Portal]. We would be happy to help out.
Thank you for contacting us, and we hope you have a great rest of your day
Hope something in that exchange helps someone reading, I’ll update when I get an updated response from Halo Support on this topic.
That looks like a set of standard responses they just send out to anyone. Must be very frustrating for you to come to a dead end like that with them closing the ticket.
Yeah, writing to Twitch was a shot in the dark, as I kinda figured it was on Halo’s end. Luckily that ticket is still open, and it seems alot of people on this thread have tickets open too - fingers crossed it gets some attention once everyone settles down from the holidays!
Look for a couple of my replies on this thread with some feedback I got from Halo Support and Twitch via email. Nothing that helped me, but maybe it will help you!
Just want to remind people in here that are potentially missing any of the unlocks (from the milked nameplate all the way to the victory pose) that contacting Twitch is NOT going to do anything for you as issue is entirely on 343. I would highly recommend creating the support ticket if you haven’t already done so and let them know what is up. I can’t imagine they’ll try sweep it under the rug and if we can assume right - tomorrow is likely the day that they return to office so fingers crossed we’ll get news as a whole all things Halo Infinite.
Read everyones having the same issue, just wanted to say I am as well. I reached out to Twitch already then just wanted to check here. I will put in a support ticket. There will definitely be a work around if we continue asking, it should be pretty easy. I honestly would really like the weapon skins as I do not want to purchase the crazy prices for other ones.
Best we can do right now is to keep encouraging those impacted to open support tickets.
I get that support can’t resolve the issue (they are first line support all they can really do is provide troubleshooting and pass information on which they do seem to be doing) but it’s frustrating that 343 could resolve this quickly and easily for people but as of yet don’t seem to have done so.
Absolutely 343 needs to investigate what went wrong so they can mitigate the risk of it happening again but we shouldn’t have to wait for that investigation to be completed, that’s 343’s problem not ours, if we can prove we’ve earned the items they should just give them to us.
If only.
Still waiting on my Animated HCS Emblem in H5 for attending HCS London in 2018. 
It was very unfortunate that the account linking between Twitch and HaloWaypoint had (has?) issues, seemingly linked but apparently wasn’t properly and so many claims went into the void.
Some of us suspected something was amiss and tried to get the word out at the time and give advice to others (that thread is now closed) but seems a lot were affected.
how is this not fixed yet? it’s been over 2 weeks since the drops
Just an update. I received a response from 343 support today:
Hey again,
We’ll give you a heads up as soon as we have any updates to share.
Thanks,
It’s not an answer to our problem, but it shows they’re checking the support tickets. They just came back from holiday break, so hopefully, this will get resolved sometime soon. I’ll report back with any new info.
Any updates on this stuff?
i got scammed out of the pistol skin too, not that i care it was ugly and basic af, not surprised either 343 is a joke.
I’ve not seen anyone reporting anything other than support saying they’ll update us if there are any developments.
For now I think it’s a case of keeping the discussion live and anyone that hasn’t yet done so raising a ticket.
They could’ve just gave out codes instead of using a wonky account based system that didn’t work for 80% of the people
Yes I am all still wondering if anyone has any informtion.
Literally just got my drops, idk what they did but they fixed it for me 
Anyone else get them today?
Just saw this and checked my rewards history on waypoint and they are there now. Will fire up game later to confirm that they are in game. Good to see this.