2) Assume that Google decided that they would no longer support IPv4 for any of their services at a specific date a couple of years in the future. […] I really expect something like this to be the next part of the end game for IPv4.

It’s never gonna happen … why would Google, or any other internet property, launch something which artificially cuts the potential revenue pool to IPv6-ready customers?

I’m with you it would be amazing and a strong driver, but it’s just not in the realm of possibility…