While researching a book on the liturgical ministry of deacons, I have been struck by the relative absence of deacons from the RCIA. While deacons are mentioned in some places, such as the specification that they can anoint catechumens, there are a number of places where both logic and tradition would indicate a role for the deacon, but the rite either gives that role to the celebrant or assigns it to an unspecified “assisting minister.” Instances of the former would be the various dismissals of catechumens and the elect in the different rites or the invitation to the elect to kneel during the scrutinies. Instances of the latter would be the litany of intercessions for the catechumens/elect that occur in the rites. Of course, in the latter case there is no problem with the deacon being the “assisting minister,” but in the former case some of the more rubrically scrupulous might not be comfortable giving the deacon parts explicitly assigned to the celebrant.
One of the notable changes in the Third Edition of the Roman Missal is the attention it gives, by comparison with earlier editions, to the role of the deacon. The obvious reason for this it that there are a lot more deacons around today than there were in 1975, when the Second Edition was issued. The same seems to have been the case in 1972, when the RCIA was promulgated. By the time the American adaptation of the RCIA appeared (1988, I believe), deacons were more prevalent in the Church in North America, but this seems not to have penetrated to the level of the liturgy. So perhaps a future edition of the RCIA might give similar attention to diaconal ministry in the rites. Of course, given the speed with which these things happen in the Church, it may well not be in my lifetime.