As far as I know the headsets are released in the countries with one of the main languages.
In the EU like Germany, France and the UK. I'm (based in The Netherlands) going to get one from the German Microsoft Store. Shipping is free as well as when I would want to return it for whatever reason.
BTW FWIW I called Acer Netherlands (because the Acer headset showed on their Dutch website) and Acer told me 'before Christmas time'.