The latter of course -- until the former group moved to consecrate its own bishops. It's that act of overt schism that placed the SSPX on a level every bit as bad as the worst of the AmChurch trimmers. This is not to impugn their love and reverence for the Trad rite, which it's well know I prefer myself. Their undoing as I hope you'll agree is in refusing to accept the humiliation and suffering that sometimes accompany obedience. To reject this mystery of suffering seems spiritually defective.
I just can't help noting that there is schism "within" the Church which is at least as bad, in most aspects, as that which has been formally recognized.
That said, there are some possible, if unlikely, reasons why bishops may have voted for this language, even if they did not actually agree with it.