This is sony's golden child, they want it to succeed, now japan hasnt seen much of it. The first day they got a trailer, second day they got a panel, now what if they got the trailers for new characters or whatever since theyve warmed up to the game and know a bit more about it?
And there's your reason for why there were no reveals.
Japan hasn't seen as much of this game as we have, so therefore TGS was a showcase of the game meant just for them. Remember, this is the first major Japanese show the game's been shown at, and chances are they hadn't seen gameplay at all before this weekend. Remember, the game didn't even look like it was going to get a Japanese release for months, so it's relatively new to them. TGS for them was like the Spike TV reveal for us.
No Japan has known about them since the heihachi/toro reveal maybe even before that. I have personally seen threads where the Japanese where discussing the game. But to be fair they don't know the game like us, they did say this was a westerner game and wouldn't sell here also what I thought was funny that some people where saying it was just a rip off of SSBB.