I am very strongly opposed to the creation of two rulesets, and opposed to allowing DJ in general. As everyone's already said, making a preset DJ CaS is a logistical hassle that is just not worth the payoff. We are not likely to get a large influx of Tekken fans who stay with the community because they have SxT, TT2 and TxS all coming out in the near future. Compare that to a single character in SC who won't even look like him.
That said, if Namco does release a Harada_TEKKEN for DLC or something, I can say with almost certainty that nobody knows if he's broken yet. It's too early in the game and no matter how good people are at theorycraft, no one can ever see all the developments ahead of time. Not everything works in practice the way it looks like it will, and I have doubts that even top players can look at a list of numbers and predict the future. It's simply too early to tell.
As I understand, it's usually EVO's policy to leave things unbanned until they're proven broken under their roof (though I assume the logistical issues of DJ will prevent him in this case regardless) which led to the giant mess that was Brawl at EVO '08. So I'm also going to say that going by EVO rules because they're EVO rules isn't necessarily the best idea. They may be very experienced at fighters in general, but I think it's likely that this community collectively knows Soul Calibur a lot better than they do.
As others have said, at this time, I don't even know why this is a debate. He's a CaS, he's out.
EDIT: Jaxel says there isn't a logistics issue, but of course I disagree. How are you even going to determine the default CaS? Who's to say he shouldn't be susceptible to combos that work on larger characters or such? Who's going to decide what he looks like? What if everyone thinks he looks like ass? Not that cosmetics really matter, but all this plus making sure every console has the exact correct CaS, dealing with the possibility of cheating, taking the time to upload the save to each console (when after a certain point, one would assume most would have everything unlocked) and a hundred other minor issues just makes it not worth it.