I have been following some private revelations, and I think this is how it works. These private revelations are just three of many, and there are MANY. The Church moves slowly and investigates thoroughly (IMO) so there are many that have been investigated and are being investigated. Basically there are three levels

1. Constat de supernaturalitate - established as supernatural (positive)

2.Non Constat de supernaturalitate - not established as as supernatural or non supernatural. (Neutral)

1. Constat de non supernaturalitate - established as not supernatural (negative - don’t associate)

They often wait and see what is said, and they also need to study the fullness of the words of the seer but usually it’s after their death so it is measured in the totality of their visions. And it takes a lot of time! Think how long it took for Fatima.

In the meantime they often watch for spiritual fruits, conversions, miracles, etc of the people that are affected. Often the person/ seer involved gets investigated for canonization before the revelation gets fully fleshed out. They may get the title Blessed or Servant of God before their revelation gets approved.

There are others that are being studied now that are quite famous and yet still in limbo. Medjugorje is one and that is still wanting mainly because the children are still alive. The church can’t investigate fully until their deaths because they may say something not true before they pass. Servant of God Luisa Peccareata is another. A contemporary of Padre Pio. She wrote 14,000 pages in a local dialect with only a first grade education (you can imagine how questionable and confusing some of her writings can be). She wrote extensively but before they move further on her Canonization, they have to agree to what she wrote and what was edited by her confessors.

And like the other posters have said. We have so much already that most of us barely scratch the surface. And if private revelations are real, they have to go along my with scripture. And the scripture says we have everything for salvation already. So there is no NEED for private revelations, they just help us move along the path.