I use a standard PS4 controller connected via USB. When I tested the game before that stream, controller support worked fine. During the stream, it didn't work at all for whatever reason.
I tested my controller today and it seems to be working fine. I thought maybe on stream I plugged the controller in after starting the game and that messed something up. But, I tried just that right now and it still worked (the title changed from 'Press Z' to 'Press A').
All that said, I think it might ultimately be a problem with my controller/cord. Lately, it's been disconnecting whenever i jostle the cord. I wouldn't worry about any bugs with the game unless someone else mentions this problem or a similar one. The fact that it's now working convinces me so. Hope this helps!
and thanks for checking out the vid/stream lol :)