it is unlikely that Apple wouldn't pulverize a prototype being discarded before it goes into the trash.
And a fairly strict-with-prototypes hardware company I used to work for has a policy of putting prototypes into electronics recycling containers, too. Yet I (and most former co-workers) have multiple pieces of prototype hardware at home.
And they end up on eBay/Craigslist on a fairly regular basis. (Not mine, not those of anybody I know - we always return them to the company's recycle bins when done with them.) And when they do, the company files requests to have the listings removed, and quietly contacts the seller to get them back. If the seller doesn't comply, they get the police involved. This happens every month. (I know someone in the "reclaim" department. I've seen one co-worker in the same department as me get fired for it.)
But because it's not Apple, it doesn't make the news.