[kdmytro]

I don't think this would be a factor. Some PCI-E 4.0 SSDs already come with metal heatsinks out of the box. If future SSDs needs addtitional cooling, this will be communicated to the buyer.

I think that the bigger question is whether 25W can be phisically supplied to the drives by contemporary motherboards. What is the power limit for the m.2 ports?

[ilyt]

At least according to wikipedia each pin is rated up to 0.5A with I think nine 3.3v pins so technically just around ~15W peak

Technically that's what U.2 (2.5 inch form factor for SSDs) would be for.

They get 5V/12V and thicker connector, I severely doubt M.2 could swing 25W as it only has 3.3V on it