I guess Canon versus non-Canon and the use of multi-verses crop up as you keep adding more shows and content to an IP. Happened of course to Marvel first, and Star Wars is dealing with a lot of Canon issues the last 2 decades, https://starwars.fandom.com/wiki/Canon#Canon_and_Legends_(20... and now Star Trek is having more of these issues.

I wouldn't be surprised to see this happen in Harry Potter soon if it hasn't already.