They are bidding on licenses to use the applicable spectrum. If the granting of a license isn’t part of what it means to “regulate commerce”, then I don’t know what is.
I don’t see any issue on this one.
Are these licenses in perpetuity, or a fixed period? Can they in turn sell them? If permanent and they can sell them, then they are selling the airways, and that's not regulating, it's selling. OTOH, if they are for fixed periods and they can't sell them, but must return them to the government if they don't use them, then they are regulating.