Did you notice that Viganò says that the position of Lefebvre implies modernism? More precise, that the idea of a future Pope correcting V2 undermines the Catholic edifice from its foundation by contradicting the anti-modernist syllabus of St Pius X?
I pointed this out a couple days ago now. Specifically, he is addressing the position articulated by Bishop Athanasius Schneider, but yes it does look like he's rejecting the R&R position. That is why I've suggested that he's slouching torwards sedevacantism.
Archbishop Vigano DOES state that there's error in Vatican II. Then he rejects the notion that the Magisterium of an Ecuмenical Council can be "reformed".
Put the syllogism together.
Major: Teaching of an Ecuмenical Council is irreformable.
Minor: There's actual error in Vatican II (he rejects the notion of resolving mere ambiguity through the hermeneutic of continuity).
Conclusion: ???
Is he leaning toward a sedevacantist-type proposition that V2 was not a legitimate Ecuмenical Council? He has REPEATEDLY referred to Francis as Bergoglio (like a sedevacantist would). He's made reference to a counterfeit anti-Church of which Bergoglio is the head. Also, since he traces the error to V2, that seems to rule out the Benedictiplenist view (where BXVI is still the legitimate pope).
This is why I get a very strong vibe that he's gone closet sedevacantist. Perhaps even now he is deep in prayer, offering the Tridentine Mass, contemplating the prudence of whether to come out with it. This logical conclusion of what he's written is almost inescapable. I wouldn't be surprised to find out about a bombshell letter declaring the See vacant.
If that's the case, he's actually "playing" this very well. He starts by calling out the pedophiles and the protection of pedophiles by Bergoglio. He gets groups like Church Militant and various conservative Novus Ordo groups backing him. Once he's established this credibility among the Novus Ordo conservative types, he than starts going after not only Bergoglio's errors but describing how they're rooted in Vatican II, that there has been a "counterfeit Church" set up as a direct result of Vatican II, and that Bergoglio aspires to be the head of this counterfeit Church. Once he gets more conservative Novus Ordites to wake up and embrace the truth/reality of this, then he could come out with the bombshell declaration that the Holy See is vacant. He's also making a name for himself outside Catholic circles with his letter to President Trump that the latter tweeted about. He's making a name for himself and establishing great credibility among conservative types. This man is, after all, a trained diplomat, and he may know exactly what he's doing. These letters of his might be part of a larger program. Imagine how this would be received by groups like Church Militant. They'd be gobsmacked.