I haven't made a return or warranty claim with CDW or for items purchased from them that I can recall; however, I had the same questions regarding the warranty on the drives. It appeared that they had copied and pasted the warranty period from the retail page, as you suggested. I had nothing better to do with a couple hours of my life, so I called their customer service center, waited on hold a while, though not that long, then asked their rep about the warranty for the Outlet listing and he said it was the standard 5-year warranty from the date of manufacture with WD. He could have been lying and it has been a long time since I processed a warranty claim with WD, but it seems worth it. When the drive comes in, I'll check it with PartedMagic or WD Data LifeGuard. As long as it passes the conveyance test and it doesn't show tens of thousands of power-on hours, I'm confident it won't be any more risky than dealing with open box items on Newegg.
Thanks for that. Very good info to know, and I appreciate you giving up your time for the cause . From what you heard, it seems its very like any other secondary market (Ebay etc.) used purchase when there's remaining warranty. The only unknown is how much warranty is left. On the plus side, most of the drives they sell at the outlet are Enterprise, so they have long(er) warranties and are made to take heavier use.
I've been buying from CDW, including the outlet, on and off for 25+ years, and never had an issue with the occasional return, so I've got no worries there. I'd just never bought anything "used". I buy a lot on Ebay though, so I suppose its no different, maybe even better since the return policy at CDW is more consistent.