As painful as it is to agree with this theory, it has a lot going for it in my personal opinion. Vexen and Xaldin had relative screentime in Chain of Memories and Kingdom Hearts II respectively and they were openly sinister.
And delving further into this, we can see the following.
Norted
Terranort (Scientist)
Braig (Guard)
Somebodies
Ienzo (Scientist)
Aeleaus (Guard)
Comatose
Even (Scientist)
Dilan (Guard)
I think Vexen was sinister mainly for his appearence, but I don't think he was much more evil than other CoM members. The only really evil thing he does in that game is allowing Larxene and Axel to manipulate Repliku's memories (and everyone tends to forget that it was Axel's idea to begin with). Other than that, he simply tried to stop Marluxia (who was a traitor), and before being killed by Axel he was about to reveal the truth about Marluxia's plan to Sora.
Zexion, on the other hand, is much more good-looking and may seem less evil, but what does he do? He too wants to stop Marluxia, but instead of helping Vexen he lets him "do the dirty work" for him and Lexaeus (but maybe if they had helped they could have succeded?). He speaks of the Organization as "the rope that binds us together" and then he leaves Vexen alone trying to oppose Marluxia. And in the end, when Riku is no longer useful, he tries to get rid of him exploiting his memories and his sense of guilt for what happened on Destiny Islands. He even appears as an illusion of Sora trying to crush his spirit.
So was really Vexen more evil than Zexion? I think that he simply appears more evil because of "hey, mad scientist" and because he looks older and uglier. I think in all the KH franchise he is the character who gets more hate because of his appearence.
In my opinion, if Ienzo is a Somebody again, so should Even.
As for the comatose state, I rewatched the cutscene in DDD where Aeleus speaks about Dilan and Even's condition, and he says: "they are conscious again but still unstable". Now, "conscious" means exactly the opposite of "comatose" to me, even though what is meant for "unstable" is unclear.
Here's the cutscene:
https://www.youtube.com/watch?v=4PiFSFg1z_k
But if they are "conscious again" it means at least that they woke up or opened their eyes.
A good way to give them some role in KH3 without hiring new voice actors could be let them be busy on a special assignment off screen (even if I'd love to see them at least once with the new graphics) or in the laboratory.
I'd love Even to restore Xion since he's her creator. He could be working on this for the entire game, appearing only in the end? I'd love it but I'm quite sure I'm not going to get it
I know they can't do everything but if KHIII is supposed to wrap up the Organization XIII/Xehanort 'Saga,' then a small scene acknowledging the status of Even and Dilan would be a bit of a shame exclude. Even seems especially important considering he created the replicas and Repliku and Xion are going to be a big part of the plot.
Totally agree. A single well-made cutscene is all it takes, surely they can find place for it somewhere?