Actually, I think that LightSquared does "own" the frequency band. But, they are only licensed to use it for satellite to ground transmissions.
The waiver granted them conditional approval to use it for terrestrial transmitters, as well. That's what was rescinded.
Every frequency band license has restrictions on the usage. The licensee can't use it however they choose, especially if it interferes with others.
‘twill be interesting to see how they monetize that.