I think there are a few misconceptions regarding heat produced when "computer processors" do certain tasks
Just because a "NEW" product does something an old product did not do, does not mean it will produce more heat.
All modern cameras have a Processor inside, however newer camera equipment with newer processors, are almost certainly made on a smaller die, or a refined process.
Both of which reduce power usage (heat output) when completing the same task as an older generation.
Will recording at 4K use more power (and produce more heat) than recording at 1080p on the same device - almost certainly Will recording at 4K use more power (and produce more heat) than recording at 1080p on a older device - due to processor advancements not necessarily.
The same goes if I encode a 4K video on my 3 year old workstation it uses more power, and produces more heat than if I encode at 1080p; However, if I upgraded my workstation with a brand new processor, due to advancements I would not be able to confirm if encoding at 4K on a new workstation uses more power or less power than encoding at 1080p on an old workstation, however I would not be surprised if it used less!
I have not seen any documentation regarding power usage for the new X-Pro processor compared to the EXR II Processor, either maximum or typical
tldr
better video quality does not necessarily mean more power usage/heat output
Personally, I see the Fuji as a photographer's tool - not a videographer's. There are plenty of "do everything" cameras out there - and Fuji, right from the start with the X100, has gone a different route. I just finally jumped into the Fuji world with a XT1, 16/1.4 and 35/1.4, and a large part of the attraction for me was the form factor of the camera: everything manual and via dials; i finally have a smaller camera (with emphasis on *camera*, not electronic-box-that-can-take-photos).
That is not to say the requirements of those who want video arent valid - it is just that *this* is not the appropriate tool for those needs. Complaining about lack of 4k video on a Fuji strikes me as akin to complaining that a 2-door sports car cannot carry a lot of luggage: that's not its forte.
Of course, if Fuji can fit it in, why not? No harm done.
