Sony is going to officially announce the Alpha a7S III on July 28, 2020. This camera is probably as highly anticipated as the Canon EOS R5 and Canon EOS R6 were.
Not much is confirmed about this new Sony, but most of the specifications should leak over the coming week or so.
Sony Addict has reported that the camera will likely come with 4K/60P, 4:2:2, and RAW video. along with passive cooling, though the camera won't have the same level of weather sealing, as it reportedly has vents on either side of the camera. This design choice helps dissipate heat without the use of a fan, which does create noise.
It is also rumored to have a 12mp image sensor, which puts it well below even the Canon EOS R6.