Might be some zoning restrictions on being able to put residential in. But adding offices is easy, as it's still commercial. Which isn't to say that they couldn't try to get it rezoned, but it's more difficult.
Zoning in the United States is out of control in most suburban-and -up places. Too restrictive. It drives a lot of our ills (megacommuting, unaffordable housing, sprawl, etc) and needs to be liberalized. Like sure, I get it, don't put a tire burning yard in the middle of a playground. But surely there's a way to avoid such outcomes without stifling all land use innovation and freedom across the board.
In our town, a local abandoned mall was torn down and renovated into a strip mall situation. As part of the deal negotiated with the city, the parking lot in back was to be used for apartments. Probably to help with revenue and to support the shops. This probably was an exception to zoning. No other apartments exist anywhere near there.
The residents were so upset they initiated a recall of council members and revoked the apartment portion of the deal (after the company had already built the mall).