Is there any way this bug can be worked on?
https://bugzilla.xamarin.com/show_bug.cgi?id=33135
Currently its impossible to release a 64 bit Windows 10 app using Xamarin Forms.
From what I can tell this would not allow your app to run on any 64 bit Windows 10 app store devices out there.
That from my understanding would probably be a majority of those devices out there.