but no idea why removing this post warranted a hostile takeover
The Mods of r/minecraft are infamous for being absolute cunts when it comes to removing shit, but there are two key examples.
They removed a post from someone who managed to create a playable version of Minecraft in Minecraft with redstone. Why? because he had a ip to the server he built it on at the start of the video, in very tiny text in the middle of 1 paragraph in a 3 paragraph preamble
A few months later, a guy called Brendan would post to the reddit about how his Girlfriend of 5 years had died and she had left a unfinished build on their realm, and asked for suggestions for what to do with it. He would make a follow up post a few days later showing off a tree he had built within her unfinished castle. A unknown moderator would remove the post for breaking a few rules. Brendan would dispute the removal, and get the very tactful response of "You've milked your girlfriends death for enough karma".
5 to 6 hours after Phoenix posted his video, a Mod would post a apology regarding the situation, a very short one but a apology none the less. People were still really mad over what happened, and the drama wouldn't die off. (Note for anyone not watching the videos, Phoenix was banned 5 years prior to the Brendan situation due to alleged self promotion.)
11 days after the initial apology, the mods would announce some changes, and would suspend the mod who sent the message for 4 weeks. People still weren't happy at this point but the drama died off after this, probably because everyone got sick of it and there was no new developments.
During the June API protest, Mojang would leave the subreddit for their own website. While this happened during the reddit blackout/protest over the API changes, I can't help but feel like it was partly because of the drama magnet the sub was. Also something I noticed in the post you linked was that the mod who sent the "Dead Girlfriend karma baiting" response actually left during the incident, and the whole "4 week suspension" was probably a cover story so people wouldn't piece together who the mod was.
Archive of the Minecraft Coup update post