"Documenting Python" references to the Apple Style Guide go back to at least Python 2.3.5's documentation, at that time to the 2001 version of the Apple Style Guide.  I was more curious if the Apple Style Guide was still being actively consulted by the documentation team or if this had become a vestigial link, being updated by rote.  So, I'd say update the link unless Georg or someone else says it is no longer relevant.