@Givinname Hello there! I'm the admin who blocked Jade on the wiki and rescinded his position as a moderator here. Also, yes, I'm admittedly one of those admins you mention who have done little to no engagement with Discussions so far due to electing to sink my free time into the wiki side of Wookieepedia. I do hope I can eventually find time to change that on my side.
I saw your comment here and felt I had to clarify some things about what happened.
"This is my biggest issue with the whole thing: it happened off site." - you even say it yourself, the Discord server is an official extension of Wookieepedia, so it happened on Wookieepedia, same how this conversation is happening on Wookieepedia.
"Not that anyone should behave differently, but this situation is an example of accidental mishap." - oh, no no no, Jade was not issued disciplinary actions for "accidentally" saying something harmful and then promptly and on-point apologizing about it, followed by being very mindful of saying anything that might aggravate the harm he had already done. No. He was blocked as an editor and removed from his position of authority on Wookieepedia as moderator because he failed to properly apologize for his actions and showed no understanding of the harm he had done and in fact kept on doing (despite multiple users explaining it to him).
"What sort of precedent is there for such a rule?" - I might answer that with a rhetorical counter-question, "What sort of precedent, really, has there been on Wookieepedia over the previous years of its existence for users receiving disciplinary actions for behavior that causes hurt to marginalized members of the site's community?" but I believe that'll be covered in my following comments.
"As far as I know it is still Fandom’s policy that global blocks cannot be issued for off site behavior, what makes it ok for The Wook to do so locally?" - see my above point it not being "off-site". If members of the Wookieepedia community are hurting its other members, it's okay for Wookieepedia's administrators to take steps to ensure that doesn't keep happening. This is also in answer to your next question about the other moderators being involved with this decision. It is not the mods' job to discipline Wookieepedia users, even other moderators, in cases like this where they cause such a major hurt to other users. It is the administrators' job.
And lastly, your comment that "it appears that the wiki is more concerned about their social reputation these days than taking care of their quality wiki editors". - Yes, Wookieepedia cares about its social reputation - we do not want to keep being seen as a bigoted and unwelcoming website in which new users who happen to come from marginalized social groups do not feel safe or are even explicitly harmed - to the point, most frequently, of leaving this community behind. How many potentially "quality editors" have we lost so far due to this, I wonder? No, Wookieepedia wants to reverse that shitty trend and take care of all of its visitors, not just the established editors, and encourage an influx of new users - by making sure that they feel welcome and can cooperate with the established ones in order to keep building this project that we all choose to be a part of.