I think they should be public. They’re already accessible for mbin posts and anyone administrating a lemmy instance. It should be clear to all users that their votes are already not private.
Someone could make a lemmy instance just to get voting behavior and make a website with cool graphs and stuff today and the only thing that could stop them is defederation. If Lemmy gets popular, this is just an inevitability.
Imagine if a large instance decided to do that today. Imagine if lemmy.world released lemmy.world/votes. Would people defederate just for that? Remember: Mbin already displays scores and I don’t think anyone has defederated over it.
Might as well put it on the interface so everyone understands it isn’t private. Rip off the bandaid.