The time for the destruction of the Church was possible-in 1960 as Sister Lucy alluded to, the inception of the Council. Siri was the "choice" of Pope Pius Xll and he was legitimately elected Pope, and received the grace of the Office. The freemasonic judaic movement against the papacy could only happen if there was A: an actual Pope that received the grace of the Office, and B: An unelected anti-pope who did NOT have the grace of the office as Pope Gregory had received it , in order to implement the destruction of the Papacy and the Church as a whole, a usurpation which could only happen by evil men not encuмbered by the Holy Ghost protecting the papacy.
If there was not a true Pope hidden, the papacy, even a freemasonic or luciferian would still have received the grace of the Office. This was true with Pope Pius lX, who was the choice of liberals and Fɾҽҽmαsσɳɾყ, but did a 180 after he was elevated to the Holy See. The evil ones could not again risk a validly elected Pope, even one of their choice, that would receive that Grace promised by Christ.
Hence Anti-popes, not validly elected as there was already a legitimate Pope in place, that were free to be as destructive as they were instructed to be.