Bishop Richard Williamson says that the lifting of the excommunications was a pre-requisite for the SSPX to enter into negotiations with the Church.
I find SSPX-types to be exasperatingly naive in their understanding of the Catholic faith.
And that's beside the anti-semitic and other "cultural" stuff.
When I ran a Catholic message board, among the people I was the least excited to talk to were Traditionalist Catholics. They were often half-knowledgeable. They cling to tradition without a really good understanding of it.
And how do you defend the Catholic Magisterium while defying it. That always struck me as ironic.