Microsoft is adding the latest stable versions of OpenSUSE and SELS (v. 15 Leap), Ubuntu 18.04 LTS, and WLinux to WSL via the Microsoft Store. The most interesting distro here is WLinux, a WSL-centric distro that costs $20. Charging for a Linux distro goes against the grain for Linux as a whole, but WLinux will offer better support and a few baked-in features out of the box.
https://www.notebookcheck.net/OpenSUSE-15-SLES-15-and-WLinux-are-coming-to-Windows-10-with-the-1809-update.357476.0.html