Just generally rambling about reasons why companies might not want to adopt user-authored changes in their main game.

There’s copyright that applies to code (which would cover copy/paste). There’s parents that apply to ideas (which might still cover cases where you didn’t use copy/paste). And there’s precedence where if you do something one way one time, others might expect you to continue doing it that way even if you intended it to be a one-off (which might overlap with both of those).