IOS 10 Release: IMPORTANT

[Agent Orange]

Is there still a way to set/change Game Center ID?
I use more than one Game Center on my iPad, switching, is that still possible with ios10?
Also on iphone6 using game center ID from old iPhone 3s that do MW anymore, so different from Apple ID on that phone ?

Apple has disabled old GC user id's in the past.... Linking to an android device might be prudent.