The Sony a7S II was a very well received camera, but it is certainly ready for the next iteration, and many creatives (particularly filmmakers) are eagerly anticipating the third version and wondering if it will actually come to market. The good news is that Sony has confirmed that a third version is indeed in development and will eventually come to market.
The recent release of the Sony a7R IV surprised quite a few people and also stoked rumors that the a7S line would no longer be updated. However, Photo Rumors is reporting on a recent Chinese interview with Sony manager Yosuke Aoki, in which he was asked about the a7S line. Aoki confirmed that there will be a third version of the camera, though he did not elaborate much on what to expect in the camera or when it might hit the market. Personally, given Sony's relatively quick refresh rates of their camera models and the time the a7S II has been on the market, I think the company is working on something potentially groundbreaking that will leapfrog the market for video shooters, especially since the camera needs to distinguish itself from the already impressive capabilities of the rest of the a7 line. Hopefully, we'll see the a7S III soon!