I never got into Harry Potter. This was not an act of moral courage. I read some of the first book as a kid, did not like it, and stopped. The Sorting Hat failed to assign me a house because I had already wandered off to look at the X-Men again.
That means I do not have the same nostalgia to untangle that a lot of people do. I understand why the books matter to them. They found the series at exactly the age when a fictional world can become load-bearing, and it followed them through childhood, adolescence, midnight release parties, movies, friendships, and the period when every personality quiz on the internet needed to know whether you were a Hufflepuff.
But “this mattered to me” and “I must continue buying every new thing made from it” are two different sentences. They have been stapled together by an entertainment industry that would very much prefer nobody notice the seam.

the old books are not asking for more money
Nobody is coming into your house to confiscate the battered paperbacks you already own. Nobody can retroactively remove the friends you made through fandom, the comfort you found in the story, or the fan fiction that was probably doing more interesting things with the premise anyway. Memory is not a subscription service. It does not stop working when you decline to purchase the reboot.
The current franchise, however, is a business. New books, games, licensed merchandise, theme-park trips, and television adaptations are transactions. J.K. Rowling remains publicly connected to the Wizarding World, and her own website describes her as a campaigner on sex and gender issues. It also promotes her privately funded legal organization, which finances cases intended to establish and enforce “sex-based rights.” That is not an inference assembled from a haunted corkboard. The fund says what it does on its own website.
So the familiar defense that buying one game or watching one new series is too indirect to matter feels increasingly unserious. Of course one purchase does not single-handedly finance a court case. That is how mass consumer products work. No individual soda purchase builds an entire bottling plant either, but Coca-Cola has somehow managed to acquire several.

there are ways to keep the memory without feeding the machine
Keep the books you have. Borrow them from the library. Buy a used copy if you absolutely need one. Read old fanfic. Rewatch the DVD that has been sitting in a storage tote since the Obama administration. Those choices are materially different from preordering the newest deluxe edition and then explaining that your money is merely symbolic.
More importantly, let the fondness be historical. We already do this with thousands of things. A childhood restaurant closes, a television show ends, a band breaks up, or a website disappears because somebody forgot to renew the domain. We are capable of loving what something was without demanding an eternal pipeline of branded content. In fact, adulthood is mostly discovering that everything you loved has either ended or been purchased by private equity.
I do not think people have to perform a public ritual of shame because they once loved Harry Potter. I do think the insistence that a beloved childhood property must remain an active consumer identity forever is a little bleak. The story already happened. You got what you needed from it. The memories are yours, and the corporation cannot repossess them.
You can just stop buying the wizard stuff.
