That's the official word from producer David Heyman (the "Harry Potter" and "Fantastic Beasts" franchises), who recently chatted with Collider about the project, and clarified the film's classification. First and foremost, it's not a remake/reboot, and it's not a sequel -- it's a prequel.
Other than that, though, Heyman admitted that he and his fellow filmmakers "are still trying to figure out how to tell that story," and more importantly, "what the story is." Here's how he explained the inspiration for the film to Collider:
“ ... [W]hen we find [Willy] at the chocolate factory doing the golden ticket, where is he before that? What leads him to that place where he’s locked himself away?… It’s how does he get there? So we’re playing around with that.”
While director Tim Burton did attempt to give Wonka a backstory in his 2005 adaptation of the classic Roald Dahl novel "Charlie and the Chocolate Factory," featuring an estranged dentist father, Heyman and co. are obviously going for something deeper with this flick. It sounds like there's still plenty of work left to do before they're ready to write a script, though -- let alone cast someone in the iconic role.
Stay tuned to see if/when this project gets off the ground.