Yes, and that is precise why freemasons need to Cardinal Siri to accept the office of papacy after being elected. And to resign invalidly under threat, duress which was invalid. And invalid pope, false pope would not receive those graces that are unique to the office of papacy. Cardinal Tisserant knew that and some others also were Canon lawyers, very good theologians.
100% ... and this is one of the most compelling considerations favoring the Siri Theory. I believe that the Masons thought they had "their man" in Pius IX (there's some credible evidence that he had joined a lodge, but it's not 100% proven). But once he was legitimately elected, and not being a manifest heretic, the graces of papal office turned him around completely. So the Masons realized that the Holy Ghost would not allow them to destroy the Church through a legitimately-elected pope. Even if he was an occult heretic, if he tried to teach a heresy via papal Magisterium, God would just cause him to drop dead.
So they needed to get someone in there that had the APPEARANCE of legitimate office (so he would be persuasive) but without the substance and the reality of papal office. How to do that?
See, if they just did not want Siri, they could easily have just threatened him before his election, or worst case just killed him off. Siri was the hands-down favorite, so he wasn't some surprise "dark horse" candidate that came out of nowhere and caught them by surprise.
But they waited until he was elected and accepted ... at which point he instantly became Pope. After that, if they applied grave duress to get him to step down against his will, that resignation would be invalid by force of law (and from common sense, etc. ... since then you could depose popes just by threatening them). On the other hand, there's no way to assume that he would have accepted it had he been threatened beforehand, where you could conclude, "He's the rightful pope since he WOULD HAVE accepted the election had he not been threatened."
So, the fact that there was no reason for them to wait until after his election and acceptance suggets that there was a calculated reason for the timing.
Some claim that Universal Acceptance would have legitimized Roncalli anyway. Completely false. That would mean the Church effectively deposed Siri ... and under no circuмstances can anyone but God (by divine law) remove a pope from office. There were a few historical precedents where a Pope had been taken into exile, but then in his absence another pope was elected ... in one case against the known public protests of the actual pope. If you claim UPA could legitimize the new pope, that would effectively mean the Church can depose popes ... which is heresy after Vatican I.