Articles scored -500 turn up among the Unread

The wiki says that articles scored -500 and below get marked as read. How come they show up among Unread/Newest First:

Also, I seem to be unable to toggle their read status. Is the low-score ‘read’ different from the usual ‘read’?

I’m on f530224.

the code for this seems to be in place. if you’ve updated the filter after the article was initially imported it might not get marked as read automatically, some filter-related things only work when the article is encountered first.