It stands to reason that other OEMs would lie to use Tesla FSD because it saves them the cost of R&D. And soon the Feds will mandate v2v and its easier for that life saving technology to implement under one operating system. Say what you want about Tesla FSD, it is not geo-fenced and works pretty good ( I'm in beta FSD).
It really is a no-brainer on letting your FSD subscription to transfer to a new vehicle, it will drive demand on newer Hardware 4&5 vehicles.