bedrock Editor can create a world in Hardcore mode, because the Hardcore mode of bedrock Edition seems to force players to use survival mode, resulting in players being able to use survival mode in bedrock Editor, allowing death:

Expected behavior:
You can create the world in hardcore mode, but you can use creative mode normally.
or
bedrock editor prohibits the use of Hardcore mode.

What actually happened:
The player is in (hardcore) survival mode.

Note:
The bug has been fixed and in version 1.21.10.21 it is no longer possible to create "projects" in hardcore mode, but this ticket is not marked as resolved