That's not how I read that sentence at all. Maybe I've just been speaking VC for too long.
What he meant was: "I'm going to get everybody in the world access to great services. Doing so means monetizing somehow. Ads will be the last way I chose to do that, but I will if it's the only way I can figure out how to achieve that goal."
You've said the same thing.
> Ads will be the last way I chose to do that
The implication is that they've exhausted all other options.