Creniac said: I guess we're ignoring Mori or whatever claiming she wore them.
Every image released by ArcSys depicting Noel has gone out of it's way to hide an upskirt shot, and we even have her CS Storyline image (when she glomps Makoto) to show that she at least isn't wearing normal underwear.
On the other hand, the intro movie for the arcade version of Continuum Shift II has a brief flash of her wearing panties (around 0:56-0:57 of the video).