Tony Northrup analyzed the companies fiscal report and the sales trend (like this one one Amazon) to conclude that:
1) The Sony E-mount and Fuji X-mount are the mounts that are the most future proof. It means in five years from now those mounts will be still well supported
2) The Canon EOS, Canon R and Nikon F mounts are also highly likely to be fine in a few years from now
3) The Fuji GFX and Nikon Z mounts are uncertain. While the reason behind a possible GFX failure is the slim amount of potential customers in case of Nikon he has a different argument: Nikon as a whole is not doing well. And the Nikon Z mount camera sales are very slow.
4) The Canon EOS-M, MFT, L-mount and Pentax mounts are doomed
I agree 90% with it. I am not so pessimistic about the Nikon Z and MFT mounts though…