I think they're specifically going with Disney Princess to make it a more exclusive club. Countless people have voiced characters in cartoons but only a select few get the Disney Princess designation.
I suppose “princess” conveys some exclusivity, but I haven’t been able to come up with anyone else who has done a Disney cartoon, princess or not, plus appear in the MCU and Star Wars.
And Mace Windu was on the Jedi council. That’s got to count for something