Yes, but that's partly my point. The teens and adults that are fans are only fans due to playing as kids, likely due to marketing to them. That's not to say any game is good or bad, but to me it's a sign of immaturity to bring it up. I'd have similar red flags with someone discussing non kid hobbies if I showed little interest. If someone wants to chat football or handbags, I'd equally want out. It's a know your audience problem. If have no problem dating a Pokemon fan and I'd probably take up the game to play with them. My issue is being so into it it's all you want to talk about on a first date. It would strine me as immature.

If we were discussing hobbies and they briefly brought it up, that wouldn't be a red flag, per se.