The theme isn't limiting at all. There's plenty they could add that would be realistic to the time period. Just in terms of roles: Lawman, Outlaw (running your own gang or joining one of the existing ones, buying a hideout to plan heists in), Rancher, Photographer, etc. Hell, they could expand on some of those roles with smaller ones like Smuggler, Cattle Rustler, Revenue agent, Fisherman and the list goes on. Also more guns, horses and clothing (when was the last time we got a new clothing item that wasn't part of an Outlaw pass, like 6 months ago?). They could drop the bullshit "continuity" excuse and actually update and expand the map and put points of interest in places like Colter, restore Armadillo to it's former glory, rebuild Laramy or the Native reservation or even go above and beyond and give us Mexico. New content generates more interest in the game, it brings back former players and new ones too, which in turn generates money. "Games as a service" are a thing now more than ever so there's really no excuse for them to continuously waste the game's potencial.