You have to understand a little bit about how the .Mil machine and it's Supply system works. Anything can get an NSN. Anything... that in itself does not make something issue. All it does is place it in the Federal supply code system. As to the Mil issue, things have changed alot in the last 10 years. Units can purchase commercial off the shelf (COTS) items using unit funds authorized by the local commander.
An example, A unit can use there funds to purchase 200 Buck folding knifes to issue to everyone in that commanders company. Does that make that Particular Knife "Military issue". No it does not go thru any official Military testing nor have to adhere to any MILSPEC, or go thru evaluation and then be selected as part of a Bid system. Could one say he has a "Military issue Buck Knife that his unit gave hims"? That is the gray area, as a typical issue item goes on a hand receipt and upon transfer out of that unit, the item would have to be turned in so it could be reissued.
Then you get in to the Classifications for what is expendable and what is durable and can be reissued. A M4 Magazine is a expendable item. They are not expected to last forever and be disposed off as a wear item (Everything has a life cycle) Many times a Soldier gets multiple issues of the same gear (e,g Clothes, web gear, magazines,glasses,) and the Supply system being what it is, tells the soldier to just keep the stuff as they are not going thru the hassle to deal with it as it will be DX''d . So now you have young Joe's hitting the pawn shops and Ebay selling stuff for a fast buck to fund a night out on the town.
These Strider knives are pretty much in that category. Do they have collector value? That has to be determined by the one who is buying it. But it does sound good to those not familiar with the Military, when your trying to sell something and get top dollar. Caveat Emptor...