Yes. As far as I know, CX does it the way you described (first sorted by elite status, then sorted by age of the request for the second sort to break the tie). As a DM, when I call CX and am waitlisted for an award redemption, they almost always say "as a DM, you are on the highest priority waitlist available...." (which I presume means almost the highest...with exceptions probably being any DMP who decides to request a redemption or maybe friends/VIP of CX, etc.)