I know B6 is expanding their mint product but I still wouldn't call them a two class airline like the legacy 3. I don't see a 2 class product becoming the new B6 strategy but rather reserved for the transcon and some international flights with a premium demand (hoping for some JFK-FLL-LIM/GRU/EZE with mint options to open up).
Though their economy product is the best domestic and EMS seats are a nice reasonably priced option.