Elvis author and researcher Joe Tunzi was asked about the reporters question about Boston being filmed and here is his answer hope it helps:
What chance do us Elvis fans have of seeing the Boston 11/11/71 (?) show on film? I've heard that many collectors have seen this, filmed in professional quality as a test for Elvis On Tour .
JOE: I have no idea where this film may be if it was filmed at all. No records indicate it was turned over to MGM. So obviously it’s not in their film archives which I have been through. Maybe the footage that some of the collectors have seen is good quality amateur-shot footage. As for the reporter who questioned Elvis about filming in Boston at the Madison Square Garden press conference, it’s quite possible that the reporter just simply meant to say Buffalo instead of Boston, considering the fact that the MGM cameras were in Buffalo on April 5, 1972 and they filmed some of Elvis’ rehearsal there. It seems that after Elvis was asked the question, he seemed puzzled by the question, not quite sure what the reporter was referring to, which leads me to this scenario.