Just a question.
Whose Feast day is celebrated on May 14th?
I will answer for you, St Matthias, apostle.
Now if the Church has placed St Matthias on the its liturgical calendar and given him the title of Apostle and gives instructions that the Common of Apostles be used is not that the ordinary Magisterium at work?
And the second reading from the Office of Readings for the day is from a homily on the Acts of the Apostles by St John Chrysostom and it seems to me that he is saying that Matthias is an apostle because the choice of him is left to Christ rather than Peter or the other apostles.
But as you have said, the Church has not made a dogmatic pronouncement (though it does appear that the ordinary Magisterium has spoken through the liturgical calendar) we are free to believe as we wish and nothing you have said persuades me to your view.
I am just confused why you are making such an issue out of it though.