Seems more like a hold up than a dialogue going on.
Here's our dream and wouldn't it be so nice if our Holy Father would just come out and declare:
"We declare, we say, we define, and we believe that outside of the Catholic Church there is no salvation whatsoever."
But alas! We know that will not happen any time soon. Dominus Flevit!
Our Holy Father does not need to do that.
Pope Eugene IV in Cantate Domino was even more explicit. No need to repeat the same thing twice. All Benedict needs to do is run into his office, print about 30 copies of said bull, and nail them to the door of every large Church in Rome.
The message would be clear. Then, he needs to do something drastic, like say "Celebrate the TLM, and according to rubrics, or you will be excommunicated."
Yes, but he could reaffirm the definition of the infallible dogma in that way still if he so choose to do so. Remember that Cantate Domino was many years ago and many will unfortunately not be familiar with it.
That's an extraordinarily accurate image...