Since this developement is just the most recent in a long conflict, we have to zoom out a bit.
The first event in this conflict I can remember was nearly a year ago when a user accused !europe@feddit.org of supporting "zionism" (meaning supporting the genocide in Gaza), which lead to feddit-org's mods defending their mods and instance. Some minor instances defeterated feddit-org which in return lead to feddit-org defederating them.
The db0-admins proposed an instance policy update on Zionist accounts. Following this, the second major event in this conflict was the admin of dbzer0 accusing feddit-org of being zionist (pro-genocide) 2 months ago. The post contained a vote about banning 7 feddit-org-communities. The majority of db0-users agreed to banning those communities, but concern was raised against defederating feddit-org as a whole.
After that vote, feddit-org as a whole has been defederated by db0.
Recent feddit-post about this: https://lem.lemmy.blahaj.zone/post/40991661
tl;dr: Leftists fighting over who is the better leftist.