I suspect this is in the category that your milage may vary, because I
haven't in several builds seen any reboot requirements for drivers and I
haven't seen any situations that are imposing reboots in other areas.
I know that the feature "Restart Manager" refers to restart to a program
that may be faultering and while it is far from perfect, its a very good
concept and it will get much better in time.
The idea for it and it's companion "Resource Exhuastion Detection and
Recovery" tries to monitor memory commit levels for stability.
I'm not sure which drivers might require a restart in concert with which
hardware, but have always harbored the impulse that if I install anything
and it is not working, a restart might help it engage or that a restart may
help period.
CH