Okay so to clarify and inform :
Nu-Skoool doing it from CH medium is his own idea. He never said it was a prerequisite. Let’s think about it. It’s a cancel to TP to Ultra. How can you react to a CH in order to perform a cancel ? The best you can do is link something if you’re fast. like far HK, sweep after a CH cr.MP.
There’s no way back if you commit to do a cr.mp U2 hoping it’ll be CH and fail to CH, game over.
Next, the U2 is famous for being the only comboable and hit-confirmable ultra Akuma have. We saw cr.mk U2 cr.mp U2 all over the place in top players video since AE2012 starting with Daigo’s Akuma show off videos. And many others since. If it’s comboable, it works without CH.
But if you’re new to this game you’re unlikely to have seen any videos about this anyway.
Finally, no I never discovered the cancel to U2, I found an easy way, a “one for all” kind of way to do it from crouch mediums and stand heavy normals because I’m lazy and found Infiltration’s way too complicated for my fingers. And this thread is right in the front page of this Akuma forum. All you need is read the thread just under yours.
And 2 threads under it you can read this Akuma's Confirmed Changes for Ultra SFIV (updated 23rd May, 2014)
It’ll answer some questions I hope.