The title is misleading. r/Minecraft is staying on Reddit, this only concerns official Mojang posts such as news and changelogs.

r/Minecraft is not going anywhere. This only concerns Mojang's official posts.

o/ Great to see this community getting the care it deserves!

Slicedlime was vocal in his support of the protest when r/Minecraft first brought it up, so I’m pretty sure this was his call to make.

Not sure about the third one, but those first two issues were resolved by massive revisions to the sub's rules (voted upon by the community) in December. Now instead of mods determining what they think the quality of the content is, they have a bot that allows users to vote on it instead.