I've seen several eBay items worded incorrectly and it's obvious on purpose to fool the buyer.
Examples are NOS booster hoses (NOS hoses that were stamped later) w/stampings worded cleverly as if it was a true left-the-factory with stamping.
And my favorites are "NOS" bolts and other tags that are obviously repros and shown with a GM box/bag in the picture with wordage like ".....we bought these in bulk from a Chevrolet dealer so you will not be getting the GM bag (or box)". Bunk....I have purchased a ton of GM parts and they even bag single screws if it isn't part of a set. The sad thing is uninformed people will fall for this and fork out good $$$$. Afterall, if it's expensive it must be real, right
The ad may be an honest mistake or someone trying to take advantage of others who doesn't know better. It will be interesting to see how this plays out after you notified them.