As of Session 19, V suspects that they have started to diverge from their original purpose (due to the presence of many high-ranking military officials in the Diamond military during the battle of Lycoris and them not sporting any Diamond insignias)
As of Session 18, the party discovered that some warforged are sentient in the way that they have differing opinions and desires
IZZIE THEORY: They either contain artificial souls or the souls of Diamond citizens (if the latter is true, then they were likely mind-wiped so they don’t remember much or anything of their previous life as a flesh-and-blood person)