Going back a bit further:

https://en.wikipedia.org/wiki/Sony_Computer_Entertainment%2C...

https://en.wikipedia.org/wiki/Sega_v._Accolade

This fact pattern (reimplementing API functions for emulation or interoperability) tracks even more closely with the Connectix case than Oracle. Google reimplemented a huge swath of the Java API surface so developers could reuse libraries, but actual applications still needed porting, so there's less protection from a fair use perspective; and even then copying APIs was still ruled to be fair use.

I just don't see how Microsoft could contort the facts to achieve a meaningfully different outcome. It doesn't matter if APIs are copyrightable if copying them is fair use for just about any purpose.