My gut reaction is that if the prelates in the Vatican had been around this sort of thing as long as some of the rest of us have, what would their discernment be?
But the bottom line is that, wisely or unwisely, the church has permitted some of it, and what goes on in healing masses is kind of like Toronto Blessing lite.
Nowhere in catholic churches have the manifestations gotten as crazy as what they have been elsewhere, but one just cannot help but wonder if the source is the same, but tailored specifically so as to gain acceptance among catholics.
Did the pope really know what he was doing when he gave this movement his blessing? I doubt he ever heard of slaying in the spirit at that time, although surely he was acquainted with the modern version of speaking in tongues if only by reading or being told about it. I would really be surprised if any regulars in the Vatican engaged in speaking in tongues as a part of their spiritual life.
The charismatics pulled the same PR game with the Papacy that the Neocatechumenate did.
They brought thousands of their group to a papal audience.
The Pope, as is customary, said a few words and then blessed the group - not as an official endorsement, just the typical thing a prelate always does, say a general blessing.
Then the organizers asked for a photo and got one.
Later it was publicized as if the Pope had explicitly authorized the movement.
People are always trying to parlay a photograph, a rosary from the Pope's hand, a polite letter, etc. as evidence of the Pope's endorsement of their beliefs.
TFP, a quasitraditionalist cult, used to do the same thing as well.
Do not take such claims at face value.