That makes a lot of sense.
I'm reminded of a UAV doing the same thing. It ran L4 for low-level control, realtime scheduling, and security, and then virtualized Linux on top of that.
Sounds unbelievably clunky on the surface, then you realize it's a remarkably useful way to abstract everything cleanly.
Many medical devices run Linux as a User-Interface... (or Windows for that matter).
The actual safety-critical portion of these systems is rarely running Linux, but rather on a bare-metal micro.