Had some discussion here with friends who've worked in the iOS ecosystem. Consensus was pretty much that virtualization is difficult and they just use MacOS on Apple hardware. I don't think I learned anything unexpected here.
For the IOS application, the development moved to Github to be able to use a third party that provides MacOS / Iphone etc as a service. That has been deemed easier and cheaper than having to figure out how to maintain Mac OS X system in a production environment or in the WMF Office It environment.