I'm not sure what you are getting at. Each carrier would have to make a deal with SpaceX. Doesn't matter if they share the same tower. If SpaceX is interfering

I'm not sure what you are getting at. Each carrier would have to make a deal with SpaceX. Doesn't matter if they share the same tower. If SpaceX is interfering with their frequency band, they are going to file a complaint with the FCC