Without Lefebvre there likely wouldn't have been the creation of loyal societies of traditionalists and Pope Benedict's effort to recover lost traditions.
They were never lost. There are plenty of clergy, especially at the highest levels of the Church, who were brought up before VII. The notion that anybody has to "recover" anything is not credible.
It is far more likely that without Lefebvre and his arrogant rebellion, the return of the Extraordinary Form would have started decades sooner than it did. It is clear that both Benedict and JPII look at that form benevolently at the very least. Lefebvre's childishness, however, made it difficult to relax restrictions without appearing to give in to (and thus encourage more) rebellion.