They're currently disabled, but they still appear for edits at /examine, and apparently they're also parsed. It shouldn't be hard, but we need to totally remove them, as it was intended.
Thinking about this and considering some recent events, I imagine that a removal out of the blue may have the potentiality to break filters using these variables. This means that we need at least to run a query for every use case of these two variables and remove them from filters. For the moment, a good point would be to hide them from dumped vars, since showing them doesn't bring any benefit to users. I'll send a patch for this in (hopefully) a couple of minutes.
Actually, we can't remove them completely. What we can do is hide them per reasons above, and stop computing them for new edits, while keeping them in old logs where they were computed.