I am aware of the Linux subsystem and projects like Linspire and ReactOS that attempt to either better compatibility between the two OSs or replicate the other but I was wondering if Microsoft were to open source the entirety of Windows what the ramifications on the Linux community would be.

Would WINE and Proton's development rapidly accelerate? Would they be necessary?

Would Windows tools like their file explorer become dominant over others in the Linux space?

Would things like NTFS be installed by default in most distros? exFAT also seemed to be (or was) in a weird legal position.

Do you think a lot of people and businesses would jump on a chimera distro that was half and half?

Bit of a weird question I know but I wouldn't even know how to word it for a web search. I could also be missing a lot due to my knowledge level on licenses and compatibility projects.

It doesn't have to be Linux specific either. If you wanted to mention how it would affect BSD or other OSs I'd be interested to hear about that as well.