As I see there is talk about the new dragon slayers, I have already said some ideas that I've thought which some folk have agreed with like Spiegel.
I wouldnt go as far as to say that the Dragons are back, as much as I would love them to be but I think they obviously must have had a backup plan incase something were to happen to there first choices, whos to say that Sting, Rogue and the Sky Dragon havent been training with the Dragons during the series ? And went active when the Time Skip started ?
They could have been keeping up on the news about each of the other Slayers, I mean Gajeel and Natsu arent exactly keeping low profiles back before the time skip.
But again just need to wait and see, I think its possible that these were just some kids who really looked up to Natsu, Gajeel and Wendy, somehow they got ahold of Dragon Lacriyma and decided to follow in there role models footsteps.
But only time will tell.
: My bro is dead. He's gone! But he's there on my back, and here in my heart! He lives on as a part of me! If you're gonna dig, dig to the heavens! No matter what's in my way I won't stop!! Once I've dug through...it means that I've won! Just who the hell do you think I am? I'm Simon. I'm NOT my bro! I'M ME!! SIMON THE DIGGER!
: Your drill is the drill that will pierce the heavens!
(All quotes from one of my favourite Anime Tengen Toppa Gurren Lagann)