Gounod was Roman, so far as I know. And I see no problem with the Schubert, which is just about the modern classical standard setting. Unless it is utter bigotry for anything not written by a professing Roman Catholic, I’m really failing to see the point of excluding great works for liturgical use written by Anglicans or Protestants (not at all the same thing).
It's lieder, an art song, not sacred, so technically it's not supposed to be used. I wish people would consider the Faure. Much more beautiful setting.