If you look the other way around (which is more relevant anyways), you can compile Mesa for Windows. However I'm pretty sure only the software renderer is available because Mesa is not capable of interfacing with the Windows kernel driver, as all the other drivers are coupled with Linux driver interfaces, iirc. (At least I'm quite certain this is the case for AMD.)
I'm also quite certain the proprietary NVIDIA driver shares a ton of code between Windows and Linux.
To add on, just because it's cool, there is a 3rd category in play with Mesa of layered drivers. Microsoft worked on and officially supports running OpenCL and OpenGL on devices which only have a DX12 driver via Mesa this fashion. Still all user space of course but not software rendering. More akin to MoltenVK from the blog post, except fully supported and maintained by the OS provider.
I'm also quite certain the proprietary NVIDIA driver shares a ton of code between Windows and Linux.