There you have it, right from the "horse’s mouth!" Indeed, there was a "setting of the stage" to destroy the dogma Extra Ecclesiam Nulla Salus. It was the modernists’ prime target!
Even the present
Catechism of the Catholic Church (which, by the way, does not even reference Karl Rahner in a single footnote, but which, instead, directly quotes, by name, from Saint Thomas Aquinas at least seven times with several dozen more footnotes) teaches that at least some individuals have been lost:
633 Scripture calls the abode of the dead, to which the dead Christ went down, "hell" - Sheol in Hebrew or Hades in Greek - because those who are there are deprived of the vision of God. 479 Such is the case for all the dead, whether evil or righteous, while they await the Redeemer: which does not mean that their lot is identical, as Jesus shows through the parable of the poor man Lazarus who was received into "Abraham's bosom": 480 "It is precisely these holy souls, who awaited their Saviour in Abraham's bosom, whom Christ the Lord delivered when he descended into hell." 481 Jesus did not descend into hell to deliver the damned, nor to destroy the hell of damnation, but to free the just who had gone before him.
http://www.kofc.org/en/catechism/