As relevant now as it had been back with the Fel drake.
Claiming the drop on Twitch is supposed to flag your WoW account for the drop “license” to be added. Sometimes there is a blip in the matrix that delays this or there is some miscommunication between Twitch’s system and Blizzards. It’s why it’s been told to reach out to Twitch to resend the claim. It’s why sometimes unlinking and relinking the accounts somehow fixes the issue. There hasn’t been any real definitive reason why sometimes it takes five minutes for one thing to be delivered, 36 hours the next between the Fel drake drop to this one.