In comes out in early January in Japan, why would they release a demo a month before it is released?
To hype people up for the game? The Dojo is already doing that. The only reason people think demos are coming is because there were demos available to play at E4All.
"Oh, demos at E4All, so they might as well allow everyone to play the demo. The people who couldn't come."
It was just a rumor. They will not release a demo.