From initial glance, it seems the problem could easily be fixed with a filesystem filter driver ( https://msdn.microsoft.com/en-us/windows/hardware/drivers/if... ) detecting modifications to paths under the Linux root directory. Actually it could be done entirely in userspace, this definitely isn't some insurmountable architectural problem.

Lolling hard at suggestions to use Cygwin as a viable alternative to WSL because of this tiny nit.

Not as simple as this because some tools create a working copy of a file when it's being modified, and then replace original file once changes are saved. Mapping these changes to the same file "identity" likely v. error prone.

It's available in the current public release, you still must enable it explicitly like other optional Windows features (like Hyper-V)