User blog comment:ADour/New MARVEL STUDIOS movies announced!/@comment-5164970-20141029065001/@comment-5164970-20141029100355

Well, if Marvel can name Captain America: Civil War, Thor: Ragnarok and Avengers: Infinity (which both come out after Guardians, by the way), why wouldn't they name Guardians of the Galaxy if it indeed did have a name?

Plus, it's not so far fetched. Marvel has Iron Man 2. Guess they figured "Guardians of the Galaxy: Probably Two Word Subtitle" was too long?