It looks as though the purported Minecraft editor mode has been leaked in a video posted to Twitter by user @RogerBadgerman, a self-proclaimed industry insider.
The video shows what does indeed appear to be a world editor/builder being used to do some pretty dramatic terraforming.
Judging from some of the comments in the Twitter thread, this is potentially not the first time footage of the Minecraft editor has been leaked.
To be clear, Mojang Studios has never officially confirmed that a world editor is coming to Minecraft at all. But as some in the Minecraft community have pointed out, there are snippets present in the game’s code that all but ensure that a world editor is being developed.
— SmokeyStack (@SmokeyStack_) November 3, 2022
At this point there has been no response from either Microsoft or Mojang Studios in regards to this potential leak. It will be interesting to see if the Minecraft editor mode, if real, eventually comes to spinoff games like Minecraft Dungeons and the upcoming Minecraft Legends.