Responses like this are infuriating. Sort of like the response to, “should we drive the speed limit?” “The government has ordered us to. That’s all you need to know.”
The Church’s discouragement seems to come from the idea that it is incorrect to suppose one names the guardian angel - whereas it has been given a name since its creation. If one does NOT suppose this, the Church’s discouragement does not seem to apply. The practice potentially allows a closer relationship of the ward to the guardian (we are incarnational creatures, and a devotional name helps us bridge the gap from proposition to experience), and if done with right intention, is in no wise contrary to the Church’s teaching.
It would be as if the Church (let us suppose) abolished the indult permitting the faithful to receive Holy Communion in the hand; someone might ask why, and the answer, “Roma locutus est”, while true, is in no wise satisfying, is insulting to the intelligence, and says nothing the inquirer did not already know.
