I haven’t read through all the comments, but it doesn’t look outdated. Upvotes/downvotes are stored in the lemmy database and also federated out to other instances, so instance admins would be able to see who upvoted/downvoted on what, even if it’s not your home instance.

Lemmy itself doesn’t expose that information through the UI or API afaict so mods wouldn’t see it, only whoever has access to the database itself.

But since the upvotes/downvotes are federated, other software like Kbin can see the same information and they do actually show who voted on something.

Definitely something to be cautious about. I’m not really sure what the solution to it will be, but I’d assume it’s something that would need to change in the ActivityPub protocol (used by lemmy/kbin/mastodon/etc) to come up with a way to federate aggregated vote tallies instead of each individual activity.