How convenient that you start the quote with the portion of the statement IMMEDIATELY FOLLOWING: "In view of the PASTORAL nature of the Council, it avoided extraordinary statements of dogmas endowed with the note of infallibility..". Moreover, according to the translation I'm reading, you also misquote him: The pope said only the "authority of the ordinary magisterium", NOT the "supreme authority". You further misquote by adding the adverb "obviously" before "authentic". The pope never said "obviously authentic", only "authentic". You really ought to familiarize yourself with the degrees of authority attributable to the theological note the Church attributes to ach teaching.