Unless you're going to force your users to install WSL up front(which is a pretty poor first contact) I think you might be better served by keeping it around.
The target demographic is developers of Linux server software. A lot of those devs today run macOS
That's a huge pain in the ass for those of us who work in things that are tied to win32(graphics, gamedev tools, etc) we happily contribute back but ripping out a working port just seems petty.
I have to maintain a separate build system for Windows, all the win32 specific code, and also test under Windows... and most of this requires a Windows license
if I can rip all of that out by outsourcing the compatibility testing to Microsoft: all the better, even if I have to add a line to the documentation requiring users to check a checkbox once in some control panel somewhere
Shouldn't you be happy that WSL will enable F/OSS devs to write cross-platform software much easier by not having to keep two sets of code?
However if you're goal is to have an impact with your software then supporting win32 is a good bet since you're going to find an order of magnitude more users on win32. You'll also probably want iOS, Android and other platforms that aren't drop-in ports for POSIX if you want to provide a reasonable interface.
Maybe OP is talking about tools installed on his/her own system only?