A question above my pay grade

A reader writes:
I read the following passage in an article from 14 year ago. It was linked to in a recent article about the 2025 meeting between Pope Francis and Patriarch Bartholomew.
If, however, Rome were to downgrade that council—and the Council of Lyons, which in A.D. 1274 issued a similar decree including the filioque—from ecumenical to a regional council of the Patriarchate of the West; if the doctrinal statements produced by those councils and the five councils before Lyons and those after Ferrara/Florence were relegated to the status of theologoumenon (respectable theological opinion) instead ofdogma (revealed truth); if Rome were to remove the filioque from all translations of the Creed as a sign of universal doctrinal unity: the Orthodox Churches would have no compelling theological reason to perpetuate the schism between Rome and Orthodoxy. For then Rome would, with such confident humility and genuine servanthood, have demonstrated its true primacy among the Churches.
Lest this modest proposal sound far-fetched, I hasten to claim no less an advocate than Pope Paul VI himself. In 1974, on the 700th anniversary of the ill-fated Council of Lyons, the Roman pontiff described that assembly not as an ecumenical council but rather as “the sixth of the general synods held in the West.” The precedent is already set. If Pope John Paul II were to issue an official “clarification” of this matter, it would surely be the crowning achievement of his pontificate—and of the millennium.
Is this even possible? Wouldn’t that amount to changing doctrine? Or would it be more like an example of doctrine developing like you wrote about in a post last week? If it is possible, wouldn’t a downgrading a dogma (revealed truth) to a theologoumenon (respectable theological opinion), as the passage above suggests, open the flood-gates for people to justifiably to some degree