I believe graduating from X doesn't mean they are no longer going to be under Alphabet rather that they've graduated from being a moonshot project under X.compa

I believe graduating from X doesn't mean they are no longer going to be under Alphabet rather that they've graduated from being a moonshot project under X.company to being their own thing, still under Google/Alphabet and all the benefits that entails. If anything I imagine its a net positive for the team, though I'm not a Googler and don't really know the internal dynamics of the situation.