Good luck with that. The 3-digit dialing numbers are under control of the FCC and Congress. We had x11 numbers since the inception of the dialing. Numbers like 411 (Directory Info) and 611 (Repair Service) were around almost from the beginning and 911 (Emergency) came to be in the 1970's.. Later 211 (Community Info), 311 (Non emergency government services), 511 (Traffic Info), 711 (TDD) and 811 (Underground Utility Marking) came along. But we ran out of those x11 numbers and Congress really wanted a new 3-digit number so they created 988 which pretty much forced 10-digit dialing on everyone because 988 was an existing exchange number in many areas. So if NYC decides they want their own 3-digit dialing number, say 977 or 486 (GUN), then the FCC will have to approve it and they may need an act of Congress to get that approval if it exceeds their current authority.
A major change like that causes major changes to the call routing system that would need to understand yet another 3-digit number and that may effect interstate dialing hence the FCC getting involved.