The only official info on this promo I could find were the official waypoint posts which stated “can be secured by purchasing any Halo or Xbox merchandise at GameStop from November 9 - December 13” and “you’ll want to save your receipts and redeem the code at halowaypoint.com/redeem”.
So I order and payed for an Infinite Master Cheif Funko figure from the Gamestop website on December 10th. No email, order details page, or anything in the package contained any form of code. I contacted Gamestop customer support and explained everything to them and they told me to show my order info to Microsoft support to get my code. I then got in touch with Microsoft support and provided screenshots of the Gamestop chat and links to the Waypoint posts. They said it was on Gamestop, not them, to provide the code and couldn’t help me (even after they asked higher up in Microsoft support).
Since those Waypoints posts (for some odd reason) where the only info on this promo (no dedicated page on Waypoint or Gamestop, no small print or terms and conditions) and I followed everything mentioned in those posts, unless I get a code, I feel I am a victim of blatant false advertising. So even if the theories are true that only physical stores where doing it (which would kinda be a bad look with all the pandemic talk anyway) that would still be false advertising as the only details on the promo said no such thing.