Perhaps I am confused because I did not notice the switch between builtins.__import__ and importlib.__import__ -- and I do not know the relation between the two, if indeed they are two and not one. What I read and understood is
* importlib.import_module doc say it calls ???.__import__;
* importlib.import_module code does not call ???.__import__;
it instead calls _gcd_import (for good reasons).

If the claim and reality disagree, because ??? is effectively the same in both statements, then either code or doc could be changed.

If importlib.__import__ and builtins.__import__ are different objects, and the doc is clear about that, then no one should expect that 'calls importlib.__import__' means 'calls builtins.__import__'.