My T/A project is a bit further ahead of yours. The shop that painted mine undercoated the wheelwells. If anything, I think they went a little light compared to how I recall it before the car was stripped. The fuel lines and brake lines are installed before the undercoating. I even remember some undercoating on my original gas tank.
I think they went a little heavy on the red paint on the underneath of the trunk floor, I seem to recall there mainly being primer or dipping under the undercoating overspray and years of grime.
Note the pinch weld blackout, something often missed in restorations. I think the shop went a little light compared to original on my car.