The interesting difference here is that these things have a bunch of processors on them. So the 'pilot' process can be essentially an interrupt service routine that keeps things sane on an interrupt that cant be masked by the Python code. So during garbage collection your UAV might stop and hover, but it would be unlikely to crash in that scenario.

Further, my experience with Micropython so far has shown it to be pretty fluid. But I would be the first to tell you I haven't challenged it all that much.