User blog comment:FairyRaven/Fairy Tail Chapter 327: My Part Too, Review and Commentary/@comment-5668006-20130412134435/@comment-3546663-20130412141754

If you look at any of the chapter blogs, starting from when we found out about the 10,000 dragons, you'll see people commenting that they thought the dragons would come from the gate. It's been the most posted theory on where they would come from the whole time we've known about them.