I've never seen anyone do it in any of the match vids or even attempt them even though it's been known for a couple of months.
I'm not disagreeing with how difficult it is, I don't even know what the combo is exactly but have seen it several times, at the same time I do know what it isn't (like hard ass stuff like '97 Yamazaki infinites etc...) but I have been wrong on occasions.
I do want to point out that the argument is somewhat moot since only you and John have been trying to do it, and it was like only for the last 3 weeks for John at least, and he's gotten in real matches, but we haven't been recording for awhile so of course it hasn't been in the videos.
As for Japanese matches a) you have to factor in how many ppl use Ash and b) how many ppl are attempting the combo. Like I said, I can't say for sure since I'm not studying that combo in particular
but I don't recall seeing them drop many combos period, so maybe they just either don't know it or just like to do it. Now if we see them trying to do it all the time and messing up, I think you made your point.