This was a point brought up in http://blog.musicbrainz.org/2015/11/17/server-update-2015-11-16/#comment-127413

Initially, I think we ought to just store a list of hidden edit IDs in localStorage, and hide them right after the page loads. The downside is that this won't persist across browsers or machines, and can't be queried by the server in any way. There's also a space limitation (but it probably wouldn't be hit in practice). From a UI perspective, hiding and unhiding edits would be instantaneous, which is nice. We can put the IDs in redis later if people want persistence.

Adding a new vote type would be the really heavy-handed way of implementing this. We'd have to update a lot of queries to filter out the edits, and if you wanted to show them again, you'd have to reload the listing (which is super slow). So I think we should use a simple and conservative implementation initially (localStorage) that works for most people.

It might make sense to only allow hiding closed edits, to encourage voting (you can always abstain if it's still open).