It is pretty unlikely Egwene is Latra Pose. While there are definite similarities between their roles at this stage of the story, the ending is likely to show major differences. After all, the last time the Pattern had a formidable opponent to the Dragon who wasn't connected to him intimately, the world was saved, but at a huge cost and only temporarily. Neither of those are desired outcomes, and I don't see why the Pattern would need to recycle Latra if it actually wants Rand and Egwene to cooperate.