I am happy to report that the items automagically showed up in my camp chest more than a day after clicking claim on the Twitch Drops page.
I started watching at the very beginning on the 3rd at 10:30 CDT (Twitch drop credit started showing up 30m sooner than they said it would) and finished and claimed two hours later. I had already linked all the accounts together.
Other than showing as having been claimed in Twitch, I saw nothing anywhere and spent the next day even trying to figure out how it was supposed to get delivered, but nobody would (or could) answer that question.
Anyhow, sometime yesterday afternoon or evening, the items showed up in the camp chest just like the Deluxe edition assets. There was again no notification or any other sort of indication, so if you're waiting and it has been less than 48 hours say, I would just wait and it will likely show up.