I believe BXVI has already rejected this. The concept is theologically fuzzy, not traditional, and should not go any further.
You mean Coredemptrix or Mediatrix?
If he did that's good. I can honestly say I would expect that from +BXVI, who is a top-notch theologian and patristic at that.
IIRC, when Marian theology started creeping into the Catholic Church, some bishops were seriously questioning it. One going as far as saying that it turns the Church into a fertility cult. A stretch, but a good point still.
Only Christ could have said “It is finished” while He was on the cross, for it to have any meaning. I think B16 is wise to reject this, and this I see as yet another “course correction” that B16 will steer the Catholic Church.