I think that's part of the reason for BS jumping around a little from chapter to chapter as things were happening at the same time. I'd also think that originally he had written everyone up to the same point time wise and then realized that it wouldn't all fit in one, or even two books, and cut Perrin's and Mat's stories short so tGS would have some nice end points. With BS's statements about overlap in ToM I would assume that we'll get to actually see Mat and Perrin's adventures so that they're caught up with the others, maybe even some of what Elayne has been up to as well. I would think it likely that Perrin will meet up with Mat in Caemlyn, maybe that's why she wanted Mat to wait, she had some idea that Perrin would be on his way. Maybe Perrin will be the third to go to the ToG, though two ta'veren may be dangerous.

As for Egwene, she still has to fulfill Elaida's Foretelling about the Dragon knowing the Amyrlin's anger, so maybe she'll tell him in person as she accuses him of Compelling AS.