As I just posted on the thread downstairs, what this statement from the Vatican REALLY means is:

The Vatican on Wednesday demanded that a prelate who denied the Holocaust recant his positions [on the Holocaust in addition to recanting on the eleventeen other matters that place all members of SSPX in “schism” with the Vatican] before being fully admitted as a bishop into the Roman Catholic Church.

That is, every priest and bishop in the SSPX has some recantin’ to do before being unsuspended from their offices in the Church; Williamson simply has one more item to recant, namely his Holocaust denial.

And if Williamson refuses to recant on the broader issues of the “schism”, he’ll remain under suspension anyway, along with the rest of the SSPX clergy, so from his POV there’s no super-urgent reason to change his views on the Shoah.

(I keep using scare-quotes around “schism” because there seems to be some disagreement in the Church whether the frosty relationship between the Vatican and the SSPX amounts to an actual schism, or just some sort of Schism Lite, or what.)