The real question is how would this be beneficial to them? Almost everyone runs production systems on either Linux or Windows, so they would be an outlier, and the only one debugging and contributing to the operating system/libraries/etc.
I've read before on HN about people using Mac hardware in production, when they needed access to macOS graphics API, but since this only concerns a software implementation, and hardware was standard until M1 processors, it's reasonable to assume that Apple could port that part of OS to Linux, if they needed to use it from servers.