OP, either you are confused, or there is something weird afoot.

All the Rouge aircraft (319, 321, and 767-300ERs) have what they call "Premium Rouge". Within North America (Canada, trans-border, and "Sun"), this is essentially "Business Class".

They all also have "Preferred Seat"s, rows 12 & 19 A&F; 12, 17 31 & 32 DEF; 12-15&27 respectively. I have no idea what "Rouge Plus" is.

If the aircraft is, in reality, a Rouge 321, rows 17 or 31 are likely the way to go. The "Bulkhead" row isn't a bulkhead, just a curtan, but might as well be, the foot room is misaligned, going from 2x2 to 3x3.

It is possible that AC is putting one of their kinda emergency leased aircraft on this route, in which case, all bets off. I got nothing.