I think, here is my theory, to why it sounds strange.

When, George "from Canada" was killed by Massino's order, who was jealous and felt threatened by him, at this point. (I call George "from Canada", the most quintessential figure, as Montreal and NYC became super rich, with their narcotic network established throough him) and prior to that, "poor boy" Joe was killed, too, who was a key figure.
Then it was said, supposedly... by Vito's family members. The Vito Rizzuto Family wanted to cut their ties altogether with NYC and answer to NO ONE!! (hmmm... NYC put him into position). Hence the phrase "6th Family".
Some NYC loyalists in Montreal tried keeping the alliance (in some miniscule fashion??). NYC was very pissed off with the notion of an independent family outside of the NYC Five Family Umbrella.

With all the hoopla surrounding Montagna. That was, I'm a firm believer now, a coincidence. Montagna happended to get deported and re-locate himself back to Montreal. All the while, NYC Families decided??? to send Vito a message while in prison. Some rumours from NYC, have said that, his son's death was a form of payment for all the years between the sterile business between Montreal and NYC.
Montagna, saw an opportunity and went after it, tagging himself up with DiMaulo and DesJardins. But, we all know what happneded there

If Vito were to speak with NYC figures, in Canada. Was there an attempt for forgiveness with the NYC families?? Maybe, Vito is on his knees genuflecting for forgiveness from the NYC Five Families before he attempts his road to recovery mission????
????