Well, Chris, it seems like you’ve answered your own question: The point is that it is all going to be the same. Sure, they’ve hired the Oscar-winning Poor Things costume designer Holly Waddington, but the shows can’t stray too far from the books (HBO is billing this as a “faithful” adaptation) and more importantly, from the film character designs that are still very much part of worldwide Harry Potter marketing. That also explains why the series is filming on the same sets the movies used at Warner Bros. Studios Leavesden. If Hogwarts looked different in the show than it does in the movies, people who bought tickets to the HP theme parks might get confused!
Columbus isn’t against the concept of the show as a whole. He’s expressed support for the project and interest in what HBO will be able to do with the show that wasn’t possible in a film. And on the podcast, he said, “It’s very flattering for me, because I’m like: That’s exactly the Hagrid costume that we designed. So part of it is really exciting. I’m excited to see what they’re going to do with it. Part of it is sort of déjà vu all over again.”
This is an ongoing problem with Hollywood’s intellectual property mining and obsession with franchise expansion—something Columbus isn’t much interested in. He’s done two Harry Potters and two Home Alones, but he really hasn’t gone back to the well all that much for someone who has made a lot of iconic, nostalgic movies. In his view, “I did it. I’ve done that, it’s time to move on. I’ve always had issues with the idea of franchise. When we did Gremlins and Goonies—that’s why I didn’t do the second Gremlins film. My attitude then is I’ve done it and it’s time to move on,” he said on the podcast. “Same with Potter. I feel like I’ve done it … I’m really proud of those films—the first three that I was involved with, and I’m moving on.” That’s a pretty rare attitude in Hollywood these days!