It is not just that this Mass is illicit. There is no doubt about that. In the Latin Rite, Quo Primum forbids any Mass but our Pius V Latin Mass.
What needs to be remembered is that the Modernist heresy has been condemned by Pius X! This "Mass," and any "miracles" from it do not matter, in the sense that we are obliged and commanded to stay away from such things as the New Mass - should even Our Lord stand on the altar and tell us to attend!!!
With due respect, what is it with this fascination of miracles, and/or continued defense of such interest in them? I wish Bishop Williamson would clearly warn souls against attending these Masses, instead of dangling miracles as possibilities of these Masses having some value. His job is to save souls, not tempt them. Good shepherd, come forth! There is so much muddle and unknowing about what is really happening here - what God intends or doesn't; indeed, the conspiracy or modernists, call them what you will, are more than capable of having a laboratory study be conclusive in any way they desire. The Bishop keeps going back to these "possibilities" instead of the reality of Church law. This Mass is absolutely illicit. Modernism is condemned. The New Mass issue is clearly decided: God forbids attendance.
Miracle or not, Rome has spoken.