It's unclear to me what this is trying to argue. So apologies if the below entirely misses your point.
Technical documentation that refers to a codebase should live and be maintained with it. Otherwise there will certainly be drift. It can obviously still happen but at least it is provable it shouldn't have.
Not maintaining accurate documents is like disabling tests because they don't pass. It's easy to do but not right.
A checked in codebase to me should be as current and correct as possible. That includes accurate documentation.
I've rarely seen documentation that isn't tied to the codebase being maintained/valued.