If Alice creates page X, and later Bob edits page Y to add a link to page X, then Alice gets a notification about this. There is no way she can stop getting those notifications, because we always notify the creator of X and Alice can't stop being the creator of X.
Instead, if we only send these notifications if Alice has X on her watchlist (i.e. notify the creator, but only if they are watching the page), then Alice has a way to opt out of these notifications, because if she unwatches X she'll stop being notified about links being made to it.
This will cause users who don't have pages they created on their watchlist to stop being notified, but since watchcreations is enabled by default all production wikis (except Commons), this would have to have been a deliberate choice: either the user unwatched the page after creating it, or they disabled this preference.