There is an important distinction between the words "for" and "through."
Case in point: Marvel Studios president Kevin Feige's recent interview with Wired.com. It's a fascinating read on how the Marvel movies are where they are today, filled with insight about the studio's future plans. And we're talking far future, based on one particular comment.
"I could arguably say what we're planning for the year 2021," said Feige. "Will that happen? I don't know. But what we planned for 2015 in 2006 is happening."
Some folks have taken Feige's comments to mean that Marvel's movie slate is planned through 2021. But nowhere in the article does Feige say "through 2021." He's talking about specific plans for the year 2021 — and that could mean just about anything, regardless of however many movies and "phases" Marvel pumps out before then.