That does not explain how Thancred manages to get there too (as he's shown running with Reborn!Minfilia under Bizzaro!Limsa Lominsa Eulmore in the trailer after all, meaning he is definetely going to the First with us - the develiopment team confirmed long ago that Thancred, along with all the Archons except Krile do not have the Echo at all, so that's either a plot oversight or something else allows him to crossover....).

Hmmmm.....