I think that even just a partial setting free of the traditional Mass would be a great step forward for the universal Church. The powerful grace contained in the Mass, presently strangled as it were by the rite of Paul VI, would start to flow again all over the world. However, it would take much more than just restoring the true rite of Mass to solve the crisis of faith in the Church.
“Ab inimico disce”, learn from your enemy, said the Latins. Why are so many Conciliar bishops in uproar at the mere possibility of the true rite of Mass being set free? Is it not because they know that if the Ark of the Alliance is allowed into their temples again, their rites of Dagon are in peril? (Read Chapter V of the first book of Samuel!) Are we with our rite of Pius V to be more afraid than they are with their rite of Paul VI?