Of course they did. They were never seriously interested in coming back, because they don’t want to submit to lawful authority.
Is the Church of Jesus fallible? SSPX says so. So that would make it a bunch of hooey, whether they change “back” to the SSPX “plan” or stay in supposed “error”. That’s some monumental pride in camels hair the SSPX is holding, it seems to me. The pope seems downright begging the kid to come back in for dinner before he catches cold (or hot). (We all know how that can happen to men).
If it comes down to a contest between Pope Benedict and Cardinal Levada, I’ll be siding with the Pope.