Some TV shows change their titles during their runs. For example, an attempted Columbo spin-off focusing on the detective's otherwise unseen wife was rebooted as Kate Loves a Mystery, which didn't help, as the show was cancelled anyway.
Given how we have an impulsive, immature president with the comportment of a 5 year old changing Lake Ontario to Lake America just on his say-so (which is wrong), the producers of South Park decided to have a little fun with that, and so, the just launched new season sees a title change to South America.....