The thing that seems super strange to me is that they don't seem to have warned people they would do this, the first comment is > This isn't very helpful, Amanda! I know that the wiki wasn't optimal, but there were many wiki pages developers like me had bookmarked for years beacuse they contained comprehensive and easy information, which is now missing. Why not just keep the wiki read-only online? Just to retain the…
I can at least see why they'd hesitate to leave things up, depending on the anticipated risk and likelihood of addressing it in reasonable time.
Edit: Downvote if it makes you feel better, but this is really how groups execute on problems like this without taking time away from other important projects. "Security issue? Extensive fixes needed? Take it down!"