SE have stated in the past they're actually planning on implementing a system where the player leads party of npc Grand Company soldiers to assist the player in dungeons/duties... but... having it consist of characters from past FF games, who have absolutely zero reason to even be in this game? No. Just, no.

Fanservice is one thing, but a line has to be drawn somewhere when there is too much of a good thing. FFXIV needs to start being it's own unique world and story and not just have fanservice fluff chucked into it whilly nilly.