That really sucks. There's a reason dedicated video cameras have fans, current tech needs it for sustained shooting. While this is likely an amazing device for video with capabilities beyond other still camera based bodies it's still that at its' heart. I'm sure they can probably spend a bunch on R&D and figure out a tweak to improve it but they're still going to most likely be very limited in what they can do due to those physical constraints.
And as a still photographer or videographer who works with shorter clips this would be a huge gut punch to miss out on it for awhile after putting down that kinda money if this delay is real.
Edit: a review just popped up on my feed and yeah that overheating is rough.
You can get just under 20 minutes of 8k which doesn't sound bad but then even with a 20 minute cool down it only is good for a couple of minutes after that. So heat dissipation is a huge issue.