A floor drain will need a trap primer, so water will need to be provided for.
Cutting concrete, and then it needs to wye into the existing drain and be vented. In your area, that vent may run through the roof. It could run a couple thousand for what seems like nothing. I'm guessing they don't want to shock you. These things aren't so bad when the home is being built, a lot tougher when it's been closed in and finished.