If it hasn’t been released how does he know what’s in it?
Cardinal Ratzinger has said the message of Akita is the same as the Third Secret.
Only months after Bishop Ito approved the Akita apparitions, Cardinal Ratzinger was interviewed on November 11, 1984 by Jesus magazine, a publication of the Pauline Sisters. Within this 1984 interview (titled "Here is Why the Faith is in Crisis"), published to millions in Italy, Cardinal Ratzinger acknowledged that he had read the Third Secret and that it speaks of "The dangers threatening the faith and the life of the Christian, and therefore the world, and also the importance of the last times." Cardinal Ratzinger said that the Third Secret had been suppressed since 1960 to avoid confusing religious prophecy with sensationalism. He also said, "But the things contained in this Third Secret correspond to what is announced in Scripture and are confirmed by many other Marian apparitions...." Howard Dee, former Philippine ambassador to the Vatican, stated that "Cardinal Ratzinger personally confirmed to me that these two messages, of Fatima and Akita, are essentially the same. (Inside the Vatican magazine, 1998) Therefore, when Cardinal Ratzinger mentioned in his interview that the Third Secret corresponds to "other Marian apparitions," this reference includes the Akita apparitions.
Here's the message of Akita, which has the same level of Vatican approval as Lourdes and Fatima:
"As I told you, if men do not repent and better themselves, the Father will inflict a terrible punishment on all humanity. It will be a punishment greater than the deluge, such as one will never have seen before. Fire will fall from the sky and will wipe out a great part of humanity, the good as well as the bad, sparing neither priests nor faithful. The survivors will find themselves so desolate that they will envy the dead. The only arms which will remain for you will be the Rosary and the Sign left by My Son. Each day recite the prayers of the Rosary. With the Rosary, pray for the Pope, the bishops and priests.
"The work of the devil will infiltrate even into the Church in such a way that one will see cardinals opposing cardinals, bishops against bishops. The priests who venerate me will be scorned and opposed by their confreres (other priests); churches and altars will be sacked; the Church will be full of those who accept compromises and the demon will press many priests and consecrated souls to leave the service of the Lord.
"The demon will be especially implacable against souls consecrated to God. The thought of the loss of so many souls is the cause of my sadness. If sins increase in number and gravity, there will be no longer pardon for them."
Pope John Paul II spoke about the Third Secret also:
The October 1981 issue of the German magazine Stimme des Glaubens reported on a discussion that Pope John Paul II had with a select group of German Catholics, in November of 1980. The following is a verbatim report of the discussion:
Text of the Published Report
The Holy Father was asked, "What about the Third Secret of Fatima? Should it not have already been published by 1960?"
Pope John Paul II replied: "Given the seriousness of the contents, my predecessors in the Petrine office diplomatically preferred to postpone publication so as not to encourage the world power of Communism to make certain moves.
"On the other hand, it should be sufficient for all Christians to know this: if there is a message in which it is written that the oceans will flood whole areas of the earth, and that from one moment to the next millions of people will perish, truly the publication of such a message is no longer something to be so much desired."
The Pope continued: "Many wish to know simply from curiosity and a taste for the sensational, but they forget that knowledge also implies responsibility. They only seek the satisfaction of their curiosity, and that is dangerous if at the same time they are not disposed to do something, and if they are convinced that it is impossible to do anything against evil."
At this point the Pope grasped a Rosary and said: "Here is the remedy against this evil. Pray, pray, and ask for nothing more. Leave everything else to the Mother of God."
The Holy Father was then asked: "What is going to happen to the Church?"
He answered: "We must prepare ourselves to suffer great trials before long, such as will demand of us a disposition to give up even life, and a total dedication to Christ and for Christ With your and my prayer it is possible to mitigate this tribulation, but it is no longer possible to avert it, because only thus can the Church be effectively renewed. How many times has the renewal of the Church sprung from blood! This time, too, it will not be otherwise. We must be strong and prepared, and trust in Christ and His Mother, and be very, very assiduous in praying the Rosary."
I don't find any of what JPII or Cardinal Ratzinger said about the Third Secret in the text released by the Vatican in 2000.