When J.K. Rowling first went public in June 2020 about her belief that transgender women are men and transgender men are women, many of the stars of the “Harry Potter” and “Fantastic Beasts” movies — including Daniel Radcliffe, Emma Watson, Rupert Grint and Eddie Redmayne — immediately spoke out in support of trans and nonbinary rights and identity. Two of the biggest Harry Potter fan communities, MuggleNet and The Leaky Cauldron, denounced Rowling’s views and…