It would seem then that there was a tradition in Alexandria where the gospel was read in private/secret among an elite membership. Origen clearly understands this to be related to Jesus's statement to the disciples with respect to the parables that there was 'those within' and 'those without' division in the community. Clement in the Letter to Theodore makes it manifest that two versions of the gospel were developed by Mark to correspond to those two communities (whether or not this is historically true or simply an explanation developed after the fact to explain the two different versions of the gospel is not clear).
That Origen wrote things privately which were later made public is very reminiscent of the situation described by Clement. In fact that Origen and Clement seemed to have moved to Palestine in the third century makes Cyril's statement in the fourth even more significant:
Of these read the two and twenty books, but have nothing to do with the apocryphal writings. Study earnestly these only which we read openly in the Church (Ταύτας μόνας μελέτα σπουδαίως, ἃς καὶ ἐν Ἐκκλησίᾳ μετὰ παῤῥησίας ἀναγινώσκομεν). Far wiser and more pious than yourself were the Apostles, and the bishops of old time, the presidents of the Church who handed down these books. Being therefore a child of the Church, trench thou not upon its statutes. And of the Old Testament, as we have said, study the two and twenty books, which, if you are desirous of learning, strive to remember by name, as I recite them. For of the Law the books of Moses are the first five, Genesis, Exodus, Leviticus, Numbers, Deuteronomy. And next, Joshua the son of Nave , and the book of Judges, including Ruth, counted as seventh. And of the other historical books, the first and second books of the Kings are among the Hebrews one book; also the third and fourth one book. And in like manner, the first and second of Chronicles are with them one book; and the first and second of Esdras are counted one. Esther is the twelfth book; and these are the Historical writings. But those which are written in verses are five, Job, and the book of Psalms, and Proverbs, and Ecclesiastes, and the Song of Songs, which is the seventeenth book. And after these come the five Prophetic books: of the Twelve Prophets one book, of Isaiah one, of Jeremiah one, including Baruch and Lamentations and the Epistle ; then Ezekiel, and the Book of Daniel, the twenty-second of the Old Testament.
36. Then of the New Testament there are the four Gospels only, for the rest have false titles and are mischievous. The Manichæans also wrote a Gospel according to Thomas, which being tinctured with the fragrance of the evangelic title corrupts the souls of the simple sort. Receive also the Acts of the Twelve Apostles; and in addition to these the seven Catholic Epistles of James, Peter, John, and Jude; and as a seal upon them all, and the last work of the disciples, the fourteen Epistles of Paul. But let all the rest be put aside in a secondary rank. And whatever books are not read in Churches, these read not even by yourself, as you have heard me say (Καὶ ὅσα [μὲν] ἐν ἐκκλησίαις μὴ ἀναγινώσκεται,ταῦτα μηδὲ κατὰ σαυτὸν ἀναγίνωσκε, καθὼς ἤκουσας). Thus much of these subjects.
“Finally, from so little sleeping and so much reading, his brain dried up and he went completely out of his mind.”
― Miguel de Cervantes Saavedra, Don Quixote