This does happen: for example in Macbook repair, it is common to buy defective motherboards, in order to salvage the chips off them (which are apple-specific, hence not purchasable elsewhere). Those boards often come from China, and often have holes drilled in them, I guess exactly to prevent them from being repaired.

It's a shame, because some of those boards could (and would, they are valuable enough) be fully repaired by a skilled repair person. Instead, the chips are picked off and the rest goes to waste.

I did buy a batch once that didn't have holes drilled, and they all turned out to have all sorts of strange, often random issues, so I suspect those were RMAs that somehow "fell off the back of a truck" and escaped the drilling.

Probably, but part of the point of outsourcing the recycling was that you wouldn't have to set up infrastructure, process and people for that. If they weren't crooked, you could even have customers ship the products directly to the recycler. To drill it first, then you are paying for shipping twice, on an item that is already worthless to you.