They did actually change the name to just Carolina, its just that the abbreviation wasn't changed because as you said the change is not really needed and the lack of political will. It was changed less than a decade ago, and still the state and the general public still references North Carolina. Florida doesn't actually have that many more people, its just that the House of Representatives is bigger. The House of Representatives has 583 seats TTL which is quite bigger than the OTL House. Since the Electoral College based upon the number of reps, the number of Electors was changed too.