Briefly? The New York / New England RBOC was called NYNEX for most of the 80's and 90's, a lot longer than it was Bell Atlantic. Bell Atlantic was just a 3 or 4 year thing after it acquired NYNEX.
You're right: NYNEX existed from 1984 (breakup of Bell System) to 1997. But Bell Atlantic was also an RBOC created in 1984. The two companies merged in 1997, with the resulting company being called Bell Atlantic (which was when NY's phone company became Bell Atlantic). Finally, Bell Atlantic acquired GTE in 2000 to form Verizon.[1]
RBOC history is so crazy when you read about it.
All these companies were broken up to eventually reform into huge corporate behemoths again, only decades later ("new" AT&T, Verizon, and Lumen / Century Link) It makes me wonder if we weren't better off just keeping the original AT&T together.