It would affect any phone mount without sufficient vibration damping, but I also suspect that there are a lot of bikes out there that wouldn't cause any problem

It would affect any phone mount without sufficient vibration damping, but I also suspect that there are a lot of bikes out there that wouldn't cause any problems regardless of the mount because they are on the less vibey side of the spectrum. Its just hard to know in advance for a given set of bike/mount/phone so better safe than sorry.