The "Second Vatican Council theorized"? I'd say, the robber council abolished the First Commandment:
The robber council mocks and accuses God and his Church: God, his First Commandment, and his Church have ridden roughshod over "the very dignity of the human person". The robber council denies dogma, infallibly declared by a Pope, using words which in an examplary way express infallibilty as defined by the Vatican Council.
Do you realize all Resistance and sedes (and in former days, the SSPX) are (or logically should be) in complete agreement with Vigano’s letter in the OP?
So far as I can tell, the only thing he has yet to do in order for all to recognize he has arrived at Tradition, is to return to exclusive use of the old sacraments.
The transformation of Vigano in the last month is very much what the conversion of Rome should look like.
This is what the SSPX should have been looking for among the Roman clergy, Curia, and pope:
An official recognition of the faulty principles of V2, and a rejection of them, and their encouragement and exhortation to the Church at large to reject them.
If that would happen, there would be no need for Resistance, and such priests would be the most valued in the Church.
Even sedes could happily be reconciled and supportive of such a movement.
But so far, Vigano stands alone.