Maybe on some sites it's fine but I feel like link previews need more modularity on size or something. Perbaps even configurable both host and client
The information density of the preview has to match, if not exceed, that of the context in which it is provided. Most of the times it's a placeholder image with less text than the URL itself.
>I think this is actually a really great design in that the name of the product can always be in the URL
he said "before". you could accomplish your goal putting the slug "after". he's making the point that having a place after which you can harmlessly delete the rest of the url is better than having embedded NOPs surrounded by identifying information (not that the average user will ever edit any url, but there is still merit in what he said that you missed, and he's not disagreeing with you)
I also like that the "id" which is an ASIN (Amazon Standard Identification Number) which is a superset of all ISBNs. This means you can just enter any book ISBN directly into the browser and end up on the right page (at least historically) instead of having to search for it.