Pehaps Our Lady came again as a reminder to us, since so many dismissed the "events" at Fatima. There are remnants of the original block rosary groups all over the world.
Perhaps Our Lady was adding emphasis to the importance of families to pray (at least daily) the Holy Rosary together, at the time in history when the ideal Catholic family was being torn apart by modernism and eventually the influx of the errors of Vatican II.
No one is required to believe in private revelation, athough the "proof" is in the behavioral outcomes such a belief leads to.
My parents knew Mrs. Hall personally as a very good Catholic woman, entirely devoted to the Faith, and the recitation of the Rosary. We always prayed a family Rosary together (as a very large family) at 7:30 pm to conclude our day. It wasn't feasible for us to get together with neighbors to pray, but I know very many people who did. Today, a great majority who adopted the practice are still Catholic. A plus in my book!
I know some of the extended Hall family. They are good, traditional Catholics, and we are blessed to know them.
p.s. If you read Mrs. Hall's testimony linked in the OP, the Blessed Mother stated specifically the occassion of praying the Rosary together was not intended to be a social event. Mrs. Hall had a personality a bit like Padre Pio....she was known to "tell it like is is."
Also, when meditating well as we should, a bomb could blow up in the next room, and it wouldn't (overly) interrupt our thoughts on the mysteries. A few extra people in the group shouldn't matter IMO, if they all have the same intention. Just my thoughts.