Background: I'm a returning LW old hat and CFAR alum and worked briefly on the LW codebase a long time ago, but am not a moderator or authority of any kind; this is my summary based on publicly-accessible data.

The edit history is not inaccessible. What happens is that whenever an article gets deleted, all of its history entries move to https://wiki.lesswrong.com/index.php?title=Delete&action=history.

Gleb Tsipursky co-founded an organization called Intentional Insights, and is doing rationality training/outreach through it. He's been posting rationality materials on Less Wrong. He created an LW Wiki page for the org in March and made occasional updates, and on November 19 it had this text. That looks pretty reasonable, although I'd remove the language suggesting a possible CFAR collaboration unless it progresses past the "has talked with" stage. On November 29 and 30 VoiceOfRa deletes it and Gleb Tsipursky restores it, then Gjm wrote an alternative article which is intensely critical and based mostly on this thread.

That thread is too involved for me to do more than lightly skim it right now, but I will highlight this comment by jsteinhart:

My main update from this discussion has been a strong positive update about Gleb Tsipursky's character. I've been generally impressed by his ability to stay positive even in the face of criticism, and to continue seeking feedback for improving his approaches.

The content of the Less Wrong Wiki is pretty inconsequential; if not for this post it wouldn't be seen. But fights like this can be very destructive to motivation, and if I were in Gleb's shoes I'd be feeling unjustly attacked. I'd prefer to see that stopped, and replaced with something more constructive.