They claim they save money either way!
First it saved money to get people out of the offices, because of reduced real estate costs. Somehow now those don't matter (and one of their six "strategic" offices is in Manhattan!) and they claim getting everyone together will save money. It will, but only because a lot of people will quit.
But I'm sure they know that, and want it to happen. Then they can replace the older workers who can't/won't relocate due to family with cheap college graduates willing to relocate, and offshore workers.