Got a source for this? Because it’s brilliant.
The paper is well worth reading, but the TL;DR if you don't wanna: the "theory" of a program (how does it fit together? What extensions/modifications would work well, how should it evolve to handle new cases, etc.) is contained only in the mind of the coder; documentation, spoken explanations, etc. are attempts at describing that theory, but they are necessarily a lossy encoding of it. Certainly attrishing everyone who knows something about a codebase would be extremely foolish under Naur's argument.
Debt, I guess to me, is code deviating from a known better theory for it to follow.