That gets back to whether the area above the garage is "living space" or just storage.
Personally I would assume that if they are dry walling the area, it is "habitable", whether they store junk up there or not.
When they do turn this into a spare bedroom, they will thank you for the receptacles and the cost is minimal at the construction phase.
I had exactly the same issue when I built the two story garage in Md and I thought I was saving money somewhere by saying the second floor was "storage" but the guy at plan review said there was nothing to be gained by doing that since the tax man just looked at the outside envelope size.
These days you might get some relief from the energy code but that will come back to you in increased utility bills down the road.
It is really hard to justify falsifying a building permit application.
