That’s often what fan films do, though in this case, the actual Harry Potter film franchise is producing prequels themselves in the form of the Fantastic Beasts series.
Considering the new series will cover five films and unspecified period of time, it’s possible the movies could eventually deal with some of the same information that this film covers.
The film is designed to primarily deal with aspects of Tom Riddle that are not dealt with in the books or movies, thus giving the filmmakers some room to play around with ideas rather than simply put established events on screen.