We have to remember that St. Patrick Day is an optional memorial in the United States. That means that it does not have to be celebrated and that the Lenten day can be celebrated instead. What usually happens when St. Patrick Day falls on a Sunday in Lent? St. Patrick is not celebrated by the Church on that day. Those places where St. Patrick Day is considered a solemnity, they have celebrated St. Patrick Day on the following Monday. St. Joseph Day is a solemnity and is transfer to Saturday, March 15th this year. We have been told in our diocese that Monday, March 17th we are to use the prayers and Mass for Monday of Holy Week. Many other important saints of our Church have not been celebrated on their day because their day fell during Holy Week or their day fell on a Sunday.
This year it just happens that St. Patrick Day is not celebrated by the Church. But is he forgotten by the Church because of this, I think not. Besides, by the end of that week, at the Easter Vigil, his name will be called out in many churches as the Litany of Saints is said or sung.