[toni-a]

Same retort applies. Canon has not been in the habit to release cameras that display (unreasonable) heat issues due to "processing".

Exactly, Canon won't release any product with flaws they have been known for reliability and this is why mainly I didn't jump Sony last year.
We known that 8K needs a lot of processing and this could generate heat, so Canon either solved the issue with the processors and then thumbs up, or they created an innovative cooling method, my wild guess is they put the cooling apparatus in the grip. The third option which is highly unlikely they limit video to two or three minutes, however, I am 100% sure there's no way they release a camera that overheats.
Again my personal guess they could add video capacity to Canon 40D, isn't it weird it has live view without video ?? however they preferred to wait... for whatever reason either marketing or because it still had flaws and it was immature...