I doubt this will work. Office buildings are structurally and architecturally very different from residential buildings. In a recent case in my home city of Ottawa, it cost the developer the same amount to retool an office building for residential as it would have for them to tear it down and rebuild a new residental tower in its place.
I don’t want to sound like an ass but… surely they’ve spoken to some developers about this and think there’s scope for it to work.
Maybe things are different in Boston. The general rule is the older the office the better it will work, and I’m betting that Boston has some pretty old office buildings.
What I can say is that this is a pretty popular political football at the moment. I wouldn’t be surprised if this it was initiated by the mayor and not the planning department.