It happened to me today, and I can say that previously capped points don't come back.
I had enough to get Mortarboard, but now I won't because the last one was a downvote. I started a rep recalculation, and that changed nothing :/ Note that although it shows 273, it still only counts as 198 because Mortarboard is for upvotes only.
See the second screenshot after I got another upvote:
