I mean honestly the only reason I would stay with Mac would be the 4 TB3 ports, the heat and performance of MacOS pales in comparison to their Windows software production counterparts.
I will say I consistently get better benchmark scores on CPU in macOS than Windows, but anything that involves the GPU is hilariously poor on macOS compared to Windows.
The developers that use XCode with Objective-C probably won't feel any difference as XCode will likely just silently compile the code into ARM (or both a la universal package from PPC days). It's too early to tell though.
there are a lot of programmers that use mac OS that don't even touch Swift or Objective-C. I'm in the web development industry, and I'd say 50% of the developers I know use apple computers for their job. Java, Ruby, even C#.
It also gives a better battery life on average compared to Windows on the same machine.
And the new Mac Pro is apparently a beast in performance and cooling.