To my understanding, members of the old Calabrian faction, D'Amicos, Piccirilli and other cells in the Montreal mafia went to Ontario and sought the help of established families for support, mainly the Violis-Luppinos but also the Siderno Group. Sal Montagna is also a large piece to the puzzle as he consolidated his power in Canada through working out deals with the Ndrangheta and support from the Five Families.
If what you're saying is true, it would be a major event to say the least. What makes me wonder is why would the Calabrian faction needed the help from outsiders when the Rizzutos where already weakened. Couldn't they have done it themselves? Or did they needed permission because Toronto and New York were still doing business with the Rizzutos?
If so, the New York and Toronto families took advantage of the situation by demaning a larger share and more influence in return for their support. It's humiliating and a sign of weakness for the once strong Montreal mafia if they are now being controlled by outsiders.
Btw, what do you know about Violi/Luppinos in Hamilton. How strong are they and how many men do they have? They seem to be very pretty mysterious.