You should update the wiki if you work on the project then. The stated roadmap goal seems fairly clear and aligns with a typical Microsoft strategy to ensure Windows remains the premium platform for its "open source" efforts.
Not being negative that is just the way it has gone in the past so you are fighting an uphill battle.
Disclosure: None
While MS is nowhere as powerful as it was in the 90s, this is exactly how MS-Java happened and why Sun went to court.
I have no disagreement with software having a primary platform. However, it would make a lot of sense for open source software to choose an open source platform as primary.
Add: I guess what I'm saying is, if you're making enhancements to an existing Open Source project which already works on non-proprietary platforms, it would be better if those enhancements work equally well on non-proprietary platforms.
Windows isn't exactly a "proprietary" platform, the OS is closed source and proprietary is but it's the wrong definition to use to describe it as a platform especially today with PAAS/IAAS.
Windows isn't free that's true but as far as PAAS (Azure/Azure-Like) goes it's not really a critical part of the pricing, and even for IAAS it's not that important.
One could also say that RHEL, SLES and the likes are proprietary distributions of Linux, they are open source, but proprietary none the less.
I can't think of one open source project that I use that is only available on OS X or primarily an OS X project.