I know this will end locked but idc. 343 was never clear about having to link your -Yoink!- account to Mixer… the fact you have to do that to when Mixer is built into the dashboard is beyond dumb. They basically said watch the halo WC on Mixer to get the voice pack and no further details than that. So major thanks for time wasted watching WC on Mixer when I could have had a better experience on Twitch. Chalking it up to 343 and -Yoink!- being out of touch the fanbase. Thanks so much!
It was explicitly stated in the mixpot instructions.