Emma Watson also had a different sort of reunion when she met the woman who plays the older version of Hermione in Harry Potter and the Cursed Child.
Members of the cast have also met previously, for instance when The Wizarding World of Harry Potter opened in Universal Studios in Studio City back in 2016.
One happened last year when Emma Watson was promoting The Circle and ran into Bonnie Wright, who played Ginny Weasley in the J.K. Rowling-based movies.
The acting world is a wee bit smaller than you might guess, and there were so very many actors who either got a start in or played a key role in the Harry Potter universe.