Why would there be crashes? The running apps will keep their already loaded binary until they're restarted. Maybe there'll be some bugs in handling shared on-d

Why would there be crashes? The running apps will keep their already loaded binary until they're restarted. Maybe there'll be some bugs in handling shared on-disk resources (cache, and maybe something else?), but I doubt that those parts change very often. That would be a reasonable reason to require a reboot, but unless those parts actually change it should be avoided.