Meh, I really don't think it's that unusual. I think people change their personae, looks, presence, social standing, level of education, perceived monetary status, a lot. People who usually do this aren't famous, or associating with famous people. So that people who did know them way back when could out them on social media.
Maybe it's because i know a few people who did this. I actually know somebody who pulled a "Hilaria." Steven and I used to work for a 5-star catering company in NYC. Steven was a very junior, assistant-chef,

from the mid-west, with an American accent. About 15 years later, now named
Stefan, he finally owned his own restaurant on the west coast. He travels to Europe every summer to bring back new recipes & techniques he's learned there. He now has an indeterminate European accent, especially when he's speaking to his rich clientele, who, I guess, think he's European since his accent and recipes are.
The other two people I know were couple people back in high school, who couldn't wait to graduate and move away to a place where no one knew them, so they could change the horribly ridiculed identities they were saddled with in elementary through high school. No accent or ethnicity change, but they changed their hair, their looks, their make-up, got rid of the coke bottle lens glasses, bought a new wardrobe, some people dumped weight, etc., so new people in their new locations would respond to them differently than the mousy, geeky, nerdy, poor, loser, etc, identity that they had.
Well, Madonna changed a lot when she dropped Ciccone from her name.