While the piece highlights a number of pre-war building that have been converted into condominiums, it also raises an interesting point regarding the changing age demographic of the Upper East Side:
"That the area might be starting to resemble other parts of Manhattan does not surprise Mr. Wolf, the architect, who believes neighborhood and status are a lot less important than before. Noting that clients in their 60s are moving downtown for the energy and clients in their 40s are moving uptown for the quiet, he said, “The boundaries have just broken down.”
It's interesting to consider how the old becomes the new, and the new becomes the old, and how the conversion of historic buildings to condominiums echoes and reflects the same change. For instance, the Times article mentions 40 East 72nd Street's conversion to a condominium in December of 2014.
A quick look through the New York City Landmark Preservation's website (40 East 72nd Street) reveals that the building was completed in 1930. Perhaps what's most fascinating about 40 East 72nd Street is its function as a symbol of the changes that are taking place in the Upper East Side across the board in real estate ––– the old (the pre-war building) making way for the new (the building's conversion into a condominium) ––– and how those changes mirror the changing demographics aacross Manhattan described Mr. Wolf.
No matter how it all shakes out, whether condominium conversions continue at the same rate, slow down, or increase, it will be interesting to see what happens, and how the market, the neighborhood, and the sellers and buyers who make their way into and out of properties on the Upper East Side will react to, move with, and enjoy one of Manhattan's most historic neighborhoods.