Stallman would point out that it's gnu/linux... but then there's a number of things he'd likely try and point out.
More seriously, this doesn't seem to be linux as much as it is bash and a handful of commonly found on linux tools - all of which you can now run on windows anyway.
If one were feeling contrary, one could point out that it's not GNU/Linux in this context... it's GNU/NT (WSL1 and cygwin). Unless we're talking about WSL2, in which case it is GNU/Linux again:)
I saw Stallman talk about a decade ago and was thrilled to be picked on, so asked a question about my Linux setup.
"I think you'll find," he interrupts me, like he's done to most of the other people asking questions "that it's actually GNU/Linux" and then fixes me with a look usually reserved for telling an adult that yes, they really have just soiled themselves.
"Actually," I took great joy in responding, "I'm running Mr Torvalds' kernel with a BSD userland, so really, I'm pretty sure I'll find it's not."
Beautiful. I've been wanting to do that, actually, but I keep having a rough time because the BSDs tend to assume you're using their kernel, libraries, and userspace all together.
More seriously, this doesn't seem to be linux as much as it is bash and a handful of commonly found on linux tools - all of which you can now run on windows anyway.
Windows users: install bash and follow along.