Note:  Cyril, like all the fathers, did acknowledge the Divine inspiration of the Old Testament Deuterocanonical books.  He merely didn't think that they were "canonical" which, in ancient times, merely meant that they should not be read publicly at Mass (i.e.part of the liturgical canon for Cyril's city-church of Jerusalem).  All "canonical" ever meant for the fathers was that something could be read at Mass within their particular Liturgy.  In the early days, each city-church had its own native Liturgy, ergo its own canon of Scriptural books.  This is what St. Cyril is presenting in his catechism for his Jerusalem flock.  This does not mean, of course, that non-canonical books could not be inspired.  For, in his very same book, Cyril also quotes Deuterocanonical passages from Daniel, 1 Maccabees, Wisdom, and Sirach, calling all them "Scripture" and citing them side-by-side with other Scriptural books listed in his canon.  To understand this in a modern context, one has to look at it like the issue of the Fatima revelations for modern Catholics.  Most Catholics clearly believe, and the Church approves, that the messages from the Virgin Mary at Fatima are inspired and of God.  However, we cannot read from Fatima at Mass in place of the Liturgically approved Bible readings.  For, as true and approved (and inspired) as Fatima is, it is not "canonical", and may not be used publicly by the Church in this way – that is, as the basis for its Liturgy.  This is how many of the fathers (mostly in the East) viewed the OT Deuterocanonicals.  They were inspired; they were Scripture, but they were not "canonical" (i.e., approved for reading in the formal Liturgy of the Church).