I think one thing needs to be reiterated:
The shutter vibration issue is not a figment of peoples' imaginations. It is real. It is a fact; it can be proven and repeated. It has anything from a very minor to massive impact on IQ. So, moving on:
The absence, presence and extent is related to many factors, but focal length and shutter speed are the key issues. Vertical/horizontal orientation is also important, as is where the tripod mounts (body base or adaptor base/lens collar).
I still own an A7R and could not care less, because I shoot short lenses almost exclusively. If I do buy the 70200 f4 OS, I have an A7 to put it on so wont have problems there.
So, although it is not remotely a problem for me, I fully recognise it is a massive problem for others. This issue does not have to be black or white. There are shades of grey in between!
FWIW, I could repeat the blur every time at certain shutter speeds with an adapted 90mm Elmarit-M. With such a lens I know I need to avoid 1/30th to 1/125th, with 1/50th to 1/80th (roughly) being the worst with my combo.