I can confirm the first part from my own experience. I ported one of my other apps to Windows (native, had to learn C# and UWP). The Windows revenue unfortunately is way, way less than Mac/iOS.
Usually it's in reverse, but it depends on the nature of the app, how well it's made, and on how it is marketed and promoted. In general, if it's something useful, its Windows version will outsell the Mac one even at a lower price level.