Has this been confirmed? Why isn't this public?
Yes, it's been confirmed by multiple sources, including some in relatively-public ways. I do not know why it hasn't been widely announced, however. Perhaps +Vigano wanted to lay low a bit since as soon as he aligns himself with the wicked h0Ɩ0cαųst-denier group, he probably looses any influence he may have on the conservative Novus Ordite crowd. But I don't know and am speculating.
Given that +Vigano was directly "consecrated" by Saint Wojtyla the Great, I'm sure there's going to be a huge political blowback. Ironically, +Williamson also conditionally ordained a priest (many years ago), Fr. Carlos Casavantes, who had been "ordained" by Wojtyla.