Moral certainty = probability so great as to allow no reasonable doubt.
Yes, there is moral certainty that V2 and the new mass aren't catholic. Which is why 99.9% of Trads agree. And even non-Trads agree. There's no "reasonable doubt" that V2 and the new mass are anti-catholic.
But it's incorrect to say that a heretical pope automatically loses his office, ipso facto, immediately, with no trial. This legal question has MUCH reasonable doubt. In fact, theologians have debated it for centuries. Ergo, moral certainty is not able to be obtained. The proof is that the various opinions among Trads is all over the place.
If you want to argue that "Fr Jim has moral certainty" on the papal status (beyond the heresy question) then you're basically saying there is no reasonable doubt. If there is no reasonable doubt, then such an opinion is no longer in the realm of personal opinion (i.e. conscience) but MUST be elevated to some kind of unquestionable truth. If there can be no doubt, then it's a fact.
So, it's illogical for (some) Sedes to say that "my conscience has moral certainty" for that is akin to using the modern saying of "it's my truth". But there's only 1 truth. Not multiple truths. Truth does not depend on your conscience, as it exists outside of your reality, and MUST APPLY TO EVERYONE. Ergo, if you say you have "moral certainty" on a topic, you are necessarily demanding that EVERYONE has the same certainty.
Or you're just using the term "moral certainty" erroneously. In which case, reasonable doubt exists, which means, you have an opinion.
It could be a VERY STRONG OPINION; it could be 90% accurate. It could even be 100% accurate, but we don't know yet. The undetermined part is we don't have any authority to get rid of the tiny amount of doubt which remains. This doubt means the topic is in the realm of opinion.