The Genovese family represented both Pittsburgh and Cleveland on the Commission. Angelo Lonardo testified about one time when traveled to New York to meet with Fat Tony Salerno. The main point was to discuss the Teamsters Union but they also got the ok to make 10 new members. It's likely, as Capeci said, that the other NY families were consulted. Same for when Philadelphia wanted to make new members. They had to be vetted with all the families.