The notion of a liturgy with a “theme” does have a place in the Roman Rite. But it’s generally not on Sunday.
[51] In the section of the lectionary entitled “Masses for Various Occasions,” we find the thematic principle at work in a way that corresponds more closely to what some liturgical planners refer to as the theme of a liturgy: e.g., readings appropriate for Christian unity, or for peace and justice. Such thematic liturgies have their place, as the lectionary title indicates, on various or special occasions, rather than at the regular Sunday liturgy.
The bishops turn a bit more attention to how they see the Scriptures interacting with the homily. Above all, the homily is not a teaching moment as one would experience in a classroom:
[52] It is to these given texts that the preacher turns to prepare the homily for a community that will gather for the Sunday liturgy. Since the purpose of the homily is to enable the gathered congregation to celebrate the liturgy with faith, the preacher does not so much attempt to explain the Scriptures as to interpret the human situation through the Scriptures. In other words, the goal of the liturgical preacher is not to interpret a text of the Bible (as would be the case in teaching a Scripture class) as much as to draw on the texts of the Bible as they are presented in the lectionary to interpret peoples’ lives. To be even more precise, the preacher’s purpose will be to turn to these Scriptures to interpret peoples’ lives in such a way that they will be able to celebrate Eucharist-or be reconciled with God and one another, or be baptized into the Body of Christ, depending on the particular liturgy that is being celebrated.
Some preachers attempt to show their intellectual prowess by using the tools of scholarship in an overt way in the homily. I mean the various ways in which one can study and interpret the Bible: historical criticism, form criticism, redaction, etc.. The bishops clearly come down against this. In fact, they assume a preacher will know the community so well so as to help them make connections between their lives and apt examples as the Lectionary presents itself to the community.
The bishops also see the Word, proclaimed and preached, as a liminal experience leading the people into the celebration of the sacraments. That’s a solidly Catholic approach, but one we would do well to remember. It also differentiates us somewhat from non-sacramental churches and their approach to liturgy. Is there ever a time in which the Word becomes the prime focus in liturgy?
(All texts from Fulfilled in Your Hearing are copyright © 1982 USCCB. All rights reserved. Used with permission.)
Catholic Sensibility 
“Is there ever a time in which the Word becomes the prime focus in liturgy?”
Well, in the sacrifice of the altar, the Word is always the prime focus in the liturgy of the Mass. Because, as Catholics and Orthodox understand, the Word is not merely inspired words of Scripture but first and foremost the second Person of the Most Holy Trinity, with the Church as his Body on earth.
Outside of the liturgy of the Mass, one may see the emphasis on the Word in Scripture in the Liturgy of the Hours. In fact, it is quite appropriate to consider the liturgy of the Mass as part of the overall Divine Office – classically, the Mass would have been offered after Prime, IIRC, and be followed by breakfast and then Terce, et cet.