Dolan can issue an interdict for when Cuomo is in the Archdiocese of New York but he can't issue a ferendae sententiae excommunication to the already latae sententiae excommunicated Cuomo.
You are absolutely right. But Dolan is the president of the USCCB. If he wanted a formal letter of condemnation, or whatever you would call it sent to Cuomo, he could damn sure get it done. He’s too much of a politician and too little of an archbishop. Archbishop Hubbard has to retire next year. Maybe his replacement will put Church teachings before politics and call out Cuomo on his open hostility to the teachings of the Catholic Church, which is causing great scandal.