I am vehemently against this idea as I don't think it serves the US or Canada's long term interests. Placing one measly team in each country does nothing to grow the sport in either country.
If we are given a similar deal to what the Italians got, I am even more against it. Our Unions should get behind PRO Rugby and help develop it commercially. The attendances in the PRO12 are pretty abysmal tbh and the spectacle of the league takes a backseat to international play.
We need to play the long game and not get in the bed with the Celts, there is commercial enterprise working in Canada and the US actively trying to bring professional rugby to the continent. We don't need inept unions trying to run a professional sport.
Lets look objectively at this proposal for just a second:
1. By North American standards, yes attendances in the Pro12 are terrible, outside the three Irish Provinces, you've got no team that draws over 10k spectators on average. We've got a large number of Junior Hockey (Age 16-21) teams that draw better attendance than the entire Pro12 and also play 3x as many games. They also have smaller rosters and far less oppressive travel Regimes than a trans-atlantic pro rugby competition would have. Even with this some of these teams struggle to break even!
2. So how will the Unions pay for this extravagant competition? Off the backs of their membership which means higher player dues and less money for grassroots development. No other national sporting union in Canada or the US is responsible for the professional game here, not even Hockey Canada, so why does Rugby think it should be different? Professional sport in North America needs deep pockets because the travel distances are massive and competition with other sports is fierce. The Canadian Football League draws on average 25,000 per game (higher than any pro rugby competition) and it struggles to maintain franchises. How will Pro12 fare if it draws a paltry couple of thousand per match?
3. Outside of British Columbia and the US West Coast, rugby is a summer sport here. Playing Rugby in the midwest US or Northern States and Canada will not work. The Pro12 would need to move their season if they hope to capture the North American market.
4. All this to say, the North American sports market is different from Europe and requires a unique approach. We have far less attachment to national identity here and fans wouldn't like their clubs taking a back seat to international development, which is sort if how the unions treat the Pro12 (as a development league). The most important thing would be putting a winning product on the field. The Toulon model would work here, the Pro12 model wouldn't. Being successful in North America also requires putting bums in the seats, so far the popularity of international rugby hasn't really transfered to the club game. Attendances across the board are rather abysmal.