To give another concrete example: Unlike the deprecated Get content endpoint, Get pages does not return the page owner.
If Atlassian follows their policy explained in the latest RFC comment, this feature gap alone should prevent a deprecation. Even if the gap were closed today, the endpoint would not be deprecated before March 2024:
If there are any gaps for a specific API endpoint, rest assured that we will only deprecate that endpoint six months after achieving parity for that endpoint.