In a properly layered system it should be possible to swap out a lower-level component without modifying higher-level component. From the very incomplete information that we're exposed to it sounds like Tesla used Mobileye hardware and some of the lower level software layers but didn't use their whole stack. So if Tesla already has its own tech for using those chips to make sense of camera feed, it is a fairly well "boxed" problem to solve. Not saying it's trivial or easy and maybe there are some patent barriers to overcome. But Tesla is confident they can do it.