I wouldn't say that lol.
Actually, should probably retract the 100% sure thing, think I was just too enthused about finding it.
It seems to match up
but there's a chance those are other seats. Can't know for sure unless I get a good view of the other seats.
I'll probably do a little more digging later, see if any other seats match that pattern.
Regardless of whether or not YMX is in Saix's seat (or anyone's seat for that matter), it doesn't point conclusively one way or the other. But it does have the potential to be a hint.
EDIT:
Aaaaand just as I suspected, there's one other match lol. And you know what? I'd say it's a better match.
In other words, there are two options:
Option A: The three Org members in the YMX shot are sitting in Zexion, Vexen, and Xigbar's seats from left to right. This would mean that from across the room YMX is sitting in Saix's seat.
Option B: The three Org members are sitting in Saix, Demyx, and Marluxia's seats from left to right. This would mean that from across the room YMX is sitting in, I would say, Axel's seat.
Both options are possible because the heights of the chairs match up with those in the screenshot. That is, the chair on the right is tallest, and the chair in the middle is the shortest.
I'm going with Option B though because of variations in height. In Option A, Xigbar's seat is significantly taller than the next highest chair (Zexion's), whereas Marluxia's chair is only a bit higher than the next highest chair (Saix's), and the heights of the chairs in the YMX shot seem to be closer to that of the latter.
So yeah, false alarm guys, sorry!
As I said it doesn't necessarily point towards anything, though it certainly can. Take it as you will.
If YMX is actually in Axel's seat, I don't think that's suggestive of anything.
And that is the danger of confirmation bias, I went into that looking to see if YMX was sitting specifically in Saix's seat when I should have just been looking to see what seat he was sitting in in general.