It’s a coincidence. The films aren’t made by the same people and don’t star the same actors - they just happen to be about the same subject.

This happens fairly often in Hollywood - two or more films will come out at the same time on the same subject. Think of Armageddon and Deep Impact a few years ago, or during the 80s when there was a glut of films about children magically becoming adults (Big, Vice Versa, Freaky Friday, etc).