I'm still getting free downloads for Clouds of Venus. Nothing has changed in that regard. Some of the territorial stores occasionally revert back to paid, so I have to contact Amazon to have them set back to free again, but that's been the case for years.
If Amazon gets rid of permafree, there will be lots of wailing and gnashing of teeth all over the place, not just a single comment about it on Quora. Also, keep in mind that Amazon's price-matching policy isn't just for books. It's for the whole store. It's a fundamental part of their business model. As long as this policy exists, and as long as other stores offer free books, then Amazon will almost certainly price-match to those free books.