Because a) it's not necessary and b) she's asking about things she should already know as of EoE.
Rei is not quantum, and never was. She's just telepathic, like many of the Angels before her. "Ascended Rei" is a freakin' ghost, all of her uber went to Yui.
Edit: Also, nice argument OMF. We don't often see eye to eye on things but I think you're on target here.