The article/research paper is one of the few i have found that gives good numbers to the disavantage of shrinking nand sizes. One of the main points in using SSD/Flash cards was that eventhough the need for more space for games grew, the aggressive shrinking would help reduce the price for the storage.
There are two different situations here. If you just want to use flash for "distribution," then the disadvantages are not big problems even if there's no new technologies. You don't really need to modify data on your distribution media (at least not much), so you can even use TLC for distribution, even though many TLC flash can only be erased for a few hundred times.
If you want to use SSD in a console, and distribute through internet downloading, of course the problem will be much bigger. If a next gen console has no optical drive, and solely use flash and internet downloading for distribution, you'll want to have a large internal storage to store these games. If you use a smaller SSD to store games, it won't be able to fit many games and gamers will have to delete some to make place for new games (and will have to re-download the deleted games later if they want to play them again). This is hardly an acceptable solution.
IMHO the only possible situation that a next gen console only have SSD as storage is that the storage is used as a cache, and games still are distributed through normal channels (i.e. optical discs or other physical media). It's possible to distribute games with flash, although they are still expensive (you are looking at about US$1 per GB and that's much more expensive than a Blu-ray disc).
But anyway, extrapolating to twenty years later based on current technology is, well, not a wise move. As I said, there are and will be more advances in flash storage, and it's not as bleak as that article said.