Yep. Just like the Church's enemies cut off grace to the world by invalidating the Novus Ordo Sacraments, they are now going to finish the job by invalidating the SSPX Sacraments.
And the SSPX is the 800 lb gorilla of Tradition. That is to say, if you took out the SSPX you'd take out most of Tradition. I think the SSPX is 4X larger (at least) than all the other small groups, sedevacantists, and independent chapels put together.
FSSP would probably be #2, if you count them as Traditional. I don't, for good reason. From the very beginning of the Trad movement, permission from the Modernists was NOT part of the movement. On the contrary! It was all about emergency jurisdiction, keeping the Faith outside the official structures, aloofness from the Conciliar Church (the New Mass, any any priests/bishops ordained in the new Rite), knowledge that Freemasons were behind Vatican II, etc.
FSSP (and now, the SSPX) says that Vatican II was just mis-interpreted. It's mostly Catholic, and the rest should be interpreted via Pope Benedict's "Hermeneutic of Continuity". BIG DIFFERENCE. If it was all a misunderstanding, then the Conciliar Church is so many LOST SHEEP: let's get ourselves in there and help them straighten it out! But if Rome is Freemason (diabolical enemy) occupied territory, then the Conciliar Church is occupied by WOLVES and we have to proceed differently -- it would certainly be madness to place ourselves under their authority in any way!
I hate adding more divisions or being less than "trad-cumenical", but I have to admit the FSSP really doesn't qualify as Trad. They are more "conservative Catholic" or "Latin Mass preferring Catholic".
In opposition to Bp. Fellay, I'd say that for TRAD Catholics, Vatican II *is* a boogeyman to be completely avoided. It IS a superheresy, as a matter of fact. The fact that he (and the entire SSPX leadership) mocks these tenets of Tradition is enough to leave the SSPX immediately, in my opinion.