Harmonix has just announced that Rock Band 4 and all of its DLC will be playable on PS5 and Xbox Series X / S. Guitar, drums and mic will all be compatible with consoles, since you just have to plug them in.
Harmonix also comes from poster this on his site:
“Our team have properly tested a bunch of old hardware on the new consoles to make sure everything works as well as they do today. So you should be able to connect all of your Rock Band 4 devices as soon as you unbox your new ones. consoles. ”
Note that the title will benefit from the new hardware since the loading times will be reduced and we will be able to notice “a significant improvement in performance”.