I actually do think there's a little difference between Ezra and The Flash and what we're talking about in this case. With The Flash, Ezra is front and center and supposedly in almost every scene of the movie. With Potter, JK is not someone you actively see. Yes, she still cashes in from the game and anything Potter related, but she got a bunch of money up front for the game and is only going to make more simply because it's a really good game.
I understand people who want to boycott the game or this new show on principal, but she was also as far removed from this game as possible. Buying the game used is a good tactic since it's an already purchased copy meaning you aren't giving JK any more money than she's already made off of the game. The issue with the show again is that, unlike the game where she was far removed, they've come out and said she's going to be closely involved. That's where I think the issue for me is and where they could've fixed the issue a lot of people are going to have with it but I digress.