You can do that in WSL already - the Windows drives are mounted and writable through the Linux file system as /mnt/c, /mnt/d, and so on. You can use Linux executables to create, delete, and modify files just as you'd expect with any file system mount (without some Linux-specific concepts like permissions).

With WSL, I've been able to run Linux-based dev and build tools and Windows IDEs at the same time on source stored in the Windows world with no issues.

On the other hand, it's true that you can't / shouldn't modify files on the Linux file system (i.e. Files outside of /mnt/...) in Windows itself since the Linux-specific concepts would get mangled. With the mounts though, there shouldn't be any need to do this.