OE does not mean new but removed from bike!!
OE is Original Equptment. Parts that a manufacturer has supplied at a far cheaper Wholesale rate in bulk to go onto bikes as they do not have to factor packaging & distributors/shipping into the costs.
Parts removed from a 'new' bike are still second hand. I would be pretty narked if i bought a 'new OE' chainset, only to find that the cranks & BB had been fitted to a frame & the arms had pedals fitted! I bought new, not second hand but in new condition.
If it doesnt match the description, its wrong.
OE if sold separately means the manufacturer washes their hands on any warranty. Any problems & its back to where you got it from
J