The title is a bit confusing depending how you read it. Edit isn't "for" Linux any more than PowerShell was made for Linux to displace bash, zsh, fish, and so on. Both are just also available with binaries "for" Linux.
The previous HN posts which linked to the blog post explaining the tool's background and reason for existing on Windows cover it all a lot better than a random title pointing to the repo.
TIL PowerShell exists for Linux.
But.. why?