User blog comment:Nerdyanimegirl225/The 3 picks/@comment-24066070-20140514105733/@comment-7418318-20140514164251

Since it hasn't even been winter (or fall for that matter) in Magnolia yet, I'd say less than two month have passed since the end of the GMG, so there's plenty of time for the Tartaros conflict to be resolved and the MC to be reformed before the matter of the next GMG has to be addressed.

That's not to say that the final conflict around Zeref and Acnologia won't mess with it, but I'm pretty sure Tartaros will be dealt with long before.

And I don't think if there'll ever be another mention of the GMG, it'll probably only be short mentions in the epilogue.