If he did not have an expectation that they would follow his timeline, he would be less likely to leak the docs to them, and possibly less likely to leak the docs at all. It's not like Snowden couldn't have just dumped all the docs on us if that was his intent.
And don't unwarrantedly put people in harms way, &c. Yes. It's called journalism. It's not perfect, but neither would an unfiltered dump have been. And it's far better than us not getting the docs at all, isn't it? Which is certainly another timeline Mr. Snowden could have chosen, at far greater personal convenience.