I'm pretty sure Doubleclick is far more 'critical' than gMail, from Google's perspective.

To be fair, ng1 wasn't good enough for such huge apps. NG2 is good enough - incredibly performant, with server-side rendering, with support of TypeScript (refactoring of huge amounts in code in IDE), with real components encapsulation and DI. And some ideas were inspired by React - such as reactive data flow ("one-way", as it called in docs).

So I think Google will do it. Google Fiber is ng2 already :)

They mentioned Adwords here, too. http://angularjs.blogspot.com/2015/11/highlights-from-angula...

I'd argue Adwords is one of the most important Google products.