It's wise to look for the potential 'catch', and the story provides it if you look, though the headline itself makes it pretty obvious by stating there will be 3,000 unaffordable residences.

In this case, the 'catch' still seems pretty solid. Sure a real estate company gets to gouge 3,000 units, but 1,000 units may well be worth that. But it does mean continued vigilance, to make sure the real estate company doesn't somehow screw up stewardship of those 1,000 affordable units.