You're going to produce that letter, right? The one that says "Priests and bishops of Campos hereby have their right revoked to offer the Mass according to the normative liturgical books of the Latin Rite"? Because that's what would be needed.
Since presumably no priest of Campos would ever concelebrate a New Mass except under duress, they only need the right NOT to participate in the New Mass. One assumes that their conscience would never allow them to do so as long as they were not having their arm twisted.
But perhaps that assumption must be thrown out the window. If Bishop Rifan willingly participated in this event, then things are even worse than we thought. It means that the only traditional diocese in the world, the only one to be preserved from the ravages of the New Order by the heroic actions of Bishop de Castro Mayer, is now being led by a traitor.