Even the Muzukashii mode of Shimedore2000 breaks the 1000-notes limit! Near the end, it's possible to hear the new sfx voice for the 4-digit combo.
Here's instead the first skilled player who managed to clear the Oni mode of the 2000 Medley without errors! It looks like the '1000-hit combo' used the same sound for '1100', '1200' and so on.