I think you should let your developers choose which OS they prefer to use, with the clause that they have to make it work them selves and warn them that getting

I think you should let your developers choose which OS they prefer to use, with the clause that they have to make it work them selves and warn them that getting help for Linux is a great deal easier. I have always been able to pick my own OS in the places I have worked so far. I would be suspicious of a place that tried to mandate any OS, even if it happened to be my preferred choice.