Yes, the Yankees have a lease agreement for the parking spaces. That's their bread and butter. In this scenario the Yankees would waive their rights to 2k of them (presumed to be the garage across the street from the GAL site), in order for the Bronx Development Parking Co (owners of the garage) to lease the land to developers.
The idea being that since they don't need that many spots, the land could be leased to a company that will generate revenue like income taxes, which would be helpful to the city. Right now the garage is mostly unused.
Imagine this: You have 100 parking spots. 5 garages with 20 spots each. You're only using 60 spots. It doesn't make sense to keep 2 empty garages running if they're never used. Instead you agree to give up the spots so the garages can be torn down and they can build something else that will be used there, like a condo, or a hotel, or a stadium maybe.
