This is not without struggles. Many times the changelog updates are missed. You can try to catch this in code review, but that could also be missed. So you can try to automatically verify the changelog was updated, but you can't force that as a pass/fail check since not all changes require a user facing change. Or your project maintainers simply copy the commit message and paste it into the changelog, and at that point, why not just automate it with something like conventional commits?

Could/should the changelog be considered a first-class deliverable with care and attention provided? I think so, but I'm not in a position to exert direct control over that across dozens of repos and team members.

I 100% agree. I found https://keepachangelog.com/en/1.1.0/ as I was writing the article which advocates for exactly this!