My biggest concerns would be privacy regarding data scrapers .

The protocol already exposes votes, so they already have that. It’s just not currently visible in the Lemmy web UI. You can, as other people on here have pointed out, already go to any kbin/mbin instance federated with a lemmy instance and view upvotes on a post or comment on that lemmy instance. Not downvotes, but kbin/mbin don’t propagate downvotes.