Note: Unfortunately the research paper linked in the article is a dead/broken/wrong link. Perhaps the author will update it later.
From the limited coverage, it doesn’t sound like there’s an actual optical drive that utilizes this yet and that it’s just theoretical based on the properties of the material the researchers developed.
I’m not holding my breath, but I would absolutely love to be able to back up my storage system to a single optical disc (even if tens of TBs go unused).
If they could make a R/W version of that, holy crap.
While I strongly agree with the idea behind your comment and gave you an upvote, at the physical layer it’s not strictly true - especially for optical discs. See https://en.wikipedia.org/wiki/Eight-to-fourteen_modulation for example.
That said, capacity listings should always be the capacity of the data that can be stored and retrieved as seen by the user, and that data would be in 8-bit bytes.