The broadcast license is also strictly speaking only necessary for over the air stations, it does not apply to cable. Cable providers get ABC for cheap due to Section 111 compulsory licensing (short version: a cable provider can retransmit an OTA station for only a small royalty), but there's nothing stopping Disney from offering ABC to cable providers for a similar cost if their license is pulled.

So, the impact at the end of the day is just lost revenue from antenna users. Cable and satellite would be unaffected. That's got to be a relatively small number in the grand scheme of things.