The Mystagogical Fathers catechize a certain way (moving from the visible rites to the invisible), catechize at different times, and provide a theological understanding of sacramental initiation that helps us to understand that the catechesis was mystagogical but the primary mystagogy was the sacrament itself and an important aspect of the process was good liturgy.
Here is an article for anyone wanting to explore the materials further: CLICK HERE.