Anytime games or other media say that shit it's always ambiguous but I assume it's like an extra decade or such. An extra century would be worth mentioning. I know Changli is a bit in age but I think she's another special case. Not really sure what's going on with Camellya but she keeps spending time in magical medical pods so maybe that's part of it. Though from what I've seen, spoilers upcoming, she seems to have been some science experiment meant to take out Rover, as told in her intimacy stories. And yeah the actual timeline seems to just be thrown in the air atm. It was pretty bad apparently, which is why they did the 180 and now everyone loves Rover instead. Yangyang was on the death bed so I can see Chixia being a bit frustrated, but still seems pretty inane to point a gun at someone who just saved everyone's lives even if you don't know him and he just sort of appeared. But now we have a genki, and a little dumb, Chixia so it's all for the better.