I have to wonder why +W felt that he needed to confirm that he is in agreement with Bp. Faure as regards sedevacantism.
Good question. There's probably a growing sympathy with sedevacantism in the Resistance ... due to Bergoglio. Heck, you have people in the Novus Ordo suggesting the same thing.
But notice +William's position ... which he claims (rightly) is identical to that of +Lefebvre. He says that -- "maybe, maybe, maybe" they are illegitimate. That we wait for the Church to make the final decision and than act in the practical order as if they're legitimate.
Does this sound like a man who holds the legitimacy of the Conciliar papal claimants to be dogmatic fact? That is the ordinary level at which Catholics must hold it, as dogma. There can be absolutely no "maybe" about it.
Consequently, neither +Lefebvre nor +Williamson are actually sedeplenists, and they most certainly do not hold their legitimacy as dogmatic fact. Hey, XavierSem, a shout-out to you, did you catch this?