I think the strong prewar hatred of communism could actually make it more interesting. I mean, we know there's gonna be a significant Chinese population there, and Canada was getting pretty mad at the US after the whole Alaska debacle. I think a communist faction popping up either out of Chinese loyalism or anti-America spite wouldn't be too out there. And plus I think there could be some people who genuinely think communism is the only way for a society to survive somewhere as unforgiving as the wasteland. It takes so much, we have to share what we have. 

It'd certainly be a polarizing faction, that's for sure. But we totally don't have to go with it. I'm just spitballing, and honestly don't know all that much about fallout lore.