I posted about it already on NB so this is kind of redundant, but there's big liability issues with them just picking whoever to do something like that and none of the big name players have any sort of resume related to this sort of work. If we had a bunch of commentated videos on YouTube or something, maybe they at least think about it, but they'd have to be crazy right now. There's the issue of language with some of us too -- I don't think it'd be much of a problem when commentating a game but obviously there's both the issue of not cursing or doing anything that might be offensive to anyone as well as explaining things in a way that people who are viewing the stream who aren't competitive players will understand. Probably not as easy as it looks. Also, Serebii and Marriland wouldn't be an upgrade over what they already have as far as lack of competitive insight.
As far as Sejun's team, both Wolfe and Ray played him, can probably figure it out once people are back home. The only Pokemon on it I know for sure is Bisharp.
EDIT: I'm actually just now watching the stream from Sunday for the first time (I didn't see it live since I was there, obviously)... some of it is worse than I expected, such as Metagross apparently being a counter to Garchomp, but props to the commentator who mentioned Scizor was a bigger part of the metagame going into the tournament and expected to be a lot more present than it was at Worlds (though that's most likely because of all the HP Fire Cresselias).
I just caught some of the funny stuff like them referring to the JAA mechanics the commentator probably got off of Chalkey's rule mechanics article he posted on NB a couple days prior, but failing to realize that was a change made about six years ago rather than just this year, but at least they tried... The one guy seems significantly less clueless than the other, he just sometimes has information backwards or whatever. It's a step up.