He's got FU money. He has fame and recognition. He has no reason to sell to Google at this point in his life.
We'd all hope so, but in practice it only depends on the board of Rubin's company and their goals.
In a startup company, everyone should be on the same page. A founder with FU money is not on the same page as an engineer risking 2-3 years for a shot at FU money. I'm almost certain that investors would look at an FU money founder differently than a ramen founder.
As a startup engineer, I have done this. There are startups. There are corporations. Both have their place and their appeal. But I'll avoid corporate startups.