In the summer of 2020, Maddie Ziegler—best known for appearing in Sia’s “Chandelier” video when she was 11—posted an earnest apology to her Twitter feed. Videos of her laughingly engaging in “ignorant and racially insensitive” behavior when she was nine were circulating online, and the internet demanded an explanation.

“I’m honestly ashamed and I’m truly sorry for my actions. The decisions I made then are absolutely not the decisions I would make today,” the then-17-year-old wrote. “We have all made mistakes in our lives and as we grow up we educate ourselves and learn to be better people.”

In her contrition, the Dance Moms alum joined in a new tradition of celebrities apologizing for the online misbehavior of their childhood selves. In recent years, we’ve se...