INteresting topic, very interesting. I’d agree that the Missal of Pius V was not banned, per se, but I would qualify whether or not it was relegated to the role of an extraordinary form. Meaning, I think it was Benedict XVI who, in a somewhat entirely unprecedented manner, introduced the idea of the Roman Rite having ordinary and extraordinary forms. I really do think this is a novelty in the history and tradition of the Roman Rite.
Yes, one could say certainly that Paul VI did not, following Vatican II and subsequent Church reforms, “ban” the so-called Tridentine Rite…but…read the Apostolic Constitution he wrote when promulgating the Missal of 1969, and it sure seems clear…just as it was at and following Trent when previous liturgies were superceded by the Tridentine reforms…that there was only one Roman Rite that the Church would be celebrating.
Now, with Trent, there were specific exceptions (Rites that could demonstrate they had been in use longer than 200 years), so even then there was not, simply, one and only one way to worship in the Roman Rite. But those exceptions were very limited and rare. Vatican II made no such exceptions that i know of, nor did the subsequent Curial documents on the proper implementation of the liturgical reform leading up to the promulgation of the Missal of Paul VI.
Anyway, just an observation. Paul VI’s Apostolic Constitution can be read here:
vatican.va/holy_father/paul_vi/apost_constitutions/documents/hf_p-vi_apc_19690403_missale-romanum_en.html
I just tend to think that the intent in the 1960s and following was that there would be one Roman Rite. I think the Church was prudent and gracious in accomodating those who refused to celebrate accordinng to the 1969 Missal, but I think the recent move by Benedict XVI is quite novel (and I am neither criticizing nor endorsing it, just sharing observations and thoughts).