There's no way the 7YW would even transpire in a timeline with a 16th century PoD. You do raise a potentially interesting point regarding Russia though; their main incentive for joining any anti-Hohenzollern camp in the future is gone, so that dynamic would perhaps be different from OTL.I do wonder,will Russia still join the 7yw on Austria's side if the Hohenzollerns don't have Prussia,give possession of East Prussia was one of their war goals.