My bishop recently stated that it is abuse to include the Hail Mary in the General Intercessions and he is right of course, it doesn't occur in the Traditional Mass (it happens in the Leonine "devotions" after Low Mass) and it shouldn't really be there in the Mass of Paul VI. The problem is that if it is not recited at Mass this important part of our Tradition will be lost. I have met recently received Catholics and children too, from dioceses, unlike mine, where bishops and priests have been rigorous in banning it from Mass, who don't know it, which presumably means they have no sense of Marian devotion devotion whatsoever! I find that deeply disturbing.
Apparently, Cardinal Heenan asked Pope Paul VI permission to include it in the Intercessions, here In England and Wales, in Mary's Dowry, apparently the Pope agreed and "models" published for the General Intercessions in England and Wales in the 1970s/80s it was always included. I must say I have never seen any "official" notification of such a permission but in those heady days Paul VI seems to have granted permission for a lot of things that were never put on paper, for example: demanding Mass should be celebrated facing the people!
It is interesting that for the Papal Liturgies during the Pope's visit here those preparing the liturgy had felt, apparently, confident enough about it to include the Hail Mary in the drafts but the Office of Papal Liturgies had removed it, presumably, because though a custom might be acceptable, even laudable in one particular country or region, if it is not "Roman" it is wrong for it to be celebrated and publicly accepted by the Bishop of Rome especially in a liturgy that will be seen outside of the region by an international audience.
Cardinal Heenan seems to have been quite wise old bird, he managed to ensure that in England and Wales, alone in the entire Church it was possible to celebrate the Traditional Mass licitly in public. He managed to ensure that in his own cathedral at least he managed to preserve something of Catholic Traditional music, and was willing not only to allow but quietly to encourage a rather rigorous and traditional interpretation of the Missal, whilst in those heady days of chaos and confusion after the Council kept liberals onside.
I cannot help thinking his intervention over the Hail Mary which was dressed up in terms of the great devotion of the English for Our Lady, was simply a recognition it was on the wane and if it was removed from public use there no devotion to Our Lady in England.
Recently the Pope stressed the importance of Mary's role at an academic conference on Our Lady in Rome, the conference itself sadly noted the loss of Marian devotion in the last fifty years. It seems what Heenan feared for England has been realised elsewhere in the world.
A loss of Marian devotion is seriously damaging to and diminishes our Christology, therefore our devotion to and worship of Christ, our understanding of the Eucharist, of the Church.
May be a Canon Lawyer can answer this:-
+ Is this a legitimate custom in E&W?
+ Is it a legitimate custom elsewhere?
+ In what sense are the General Intercessions part of the Liturgy, there is no authorised text, only "models".
+ At what point does deviation from the model actually become an "abuse".