I think it was Arcbishop Tucho Fernandez who explained, early in this potificate, that when the Pope realised time was getting short, he would act more speedily (can anyone see a link to this?).
I had a look at PF's Corpus Christi Liturgy; and thought how much older and unsteady he looked.
Is that why he has now decided to attack the Liturgy?
Could it be that he was unwilling to demolish Summorum Pontificum while Pope Benedict was still alive .... but now he realises it's too risky to wait much longer?