They probably follow both based on convenience. Keep in mind that these groups are originally Calabrese and have 'Ndrangheta ties and roots, but when they were migrating to Canada, the area was under the American Mob control, which has LCN roots.

Technically speaking, the Buffalo family called the shots in Southern Ontario back in the day. All these families answered to Magaddino one way or another. Eventually the American LCN weakened while these groups strengthened their ties with their original families back home that were becoming more powerful. The independence in Montreal started a lot sooner, and eventually it happened in Southern Ontario too when Vito decided to take out Pappalia. That was pretty much the end of Buffalo's control. The Musitano decided to be connected with the Rizzutos, which were LCN.

Now you have the Luppino family, which are independent and do have 'Ndrangheta roots, but they probably have a lot of members among them (Like the Violi son's for example) that still carry the Pappalia banner to keep ties to the American LCN through Buffalo. I mean it's better to have more allies and connections than not, so Im sure something of such nature is taking place.