I am pretty sure it's wrong. I just made a comment about this on the author's article. He claims information N~rm, but for any normal material you have mass proportional to r^3. So N~r^4, not r^2 as the author claims.
Black holes and information is a thorny issue, see e.g. [1]. So I suspect something went awry in the argument when (s)he brought quantum gravity into it.
[1]: https://en.wikipedia.org/wiki/Black_hole_information_paradox