(Backblaze engineer here.) I have no magic crystal ball, but we do have more than 10,000 hard drives spinning in our datacenter, some for 5 years now. We have collected some pretty detailed statistics regarding failure rates vs. drive brand (and 20 other metrics). We really don't see the correlation you imply (shucked consumer drives failure rates). I'm hoping to do a blog post about what we have found regarding drive failure rates, but here is a TL;DR summary: drives fail approximately 1 - 5 % each year, your application and RAID architecture and monitoring strategy MUST compensate for that with no data loss.
Another way to look at it is they potentially found an inexpensive form of credit. They save money now and might have to repay it back later -- the interesting question will be how much "credit" they'll have to "repay" because of a higher failure rate.
I hope they're keeping some basic metadata about the shucked drives, so they can compile some statistics for us. It would be fascinating to see what the lifespan of these drives will be over the next few years!
That could be a lot of liability they're holding, since they voided the warranties on the externals by shucking them. So they could wind up paying twice for failed HDDs = $130 + $130 + $25 in gas and wage to pay someone to drive around to pick these up = $285 or so per HDD?
Failure rates are still likely to be low (<5% per annum)
I've only ever bought five external drives in my lifetime. Incidentally, all of them have been "shucked" over the years, and none of them have failed. They vary from 3-5 years old.
In fact, the only two drives I've had fail on me were OEM packaged, so based on my anecdotal, statistically insignificant personal experience you could even say the opposite, that external drives are more reliable than their OEM counterparts.
You never know. Perhaps the additional packaging prevents damage to the drives in transit, and the process of installing software on the drives (as I believe some manufacturers do with external drives) provides another opportunity to quality check the drives.
*Yev from Backblaze here: I can now purchase from Costco again, so all is well on that front. Even with a price at or around your calculated $285, that is still half as expensive as the $600 per drive we were once quoted during the crisis.