Fairy Tail Thread (Spoilers)

The thing is that besides Lucy, Natsu, Wendy, Mira, Yukino, Gerard, Ultear, Meredy and Arcadius, everyone is at the plaza, way too far.

Not everyone, we don't know how far some of the people are away. Only Fairy Tail are at the plaza, and we don't know where the other guilds, we don't know where everyone else is. That said, there are other options. For instance, we know Jellal asked Laharl and Mest something. Perhaps he was getting them to prepare Etherion to fire on the castle.

And of course that Igneel flashback this arc had him specifically state that The dragon king festival was going to happen soon: He was probably talking about the dragons from the past managing to get through the gate. And he said he was going to take action soon.

After all, these dragons are clearly from the *hate humans* side who were fighting a war against the ones who trained dragon slayers, and I doubt that Igneel and co. would just let them go to the future to avoid losing.