Taking a wild guess here, but its probably canon in the prevails verse that newly crowned royalty chose a 'Name of Power', or 'Regnal Name' to recognise their second person as a princess (their public person) to differentiate them from their private person. Think of it like Catholic Popes (or indeed, Christian Bishops in general) who take on a new name when they reach the office. The Russians Tzars and the English royals do the same.
I don't like this new art style you're going with. I like the more smooth art style you had before but this is to chubby and feels kinda ridiculous. You can keep on the children, that looks cute but on fully grown ponies (Especially alicorns) it's just stupid. I can't take it seriously