I know to the contrary, they remain to the present day.
But while Catholic Christendom had no doubt as to the reality of these Saints, Catholic scholarship was by no means positive as to the authorship of the Legend of the Saints. The Greek MSS. attributed it to "John, Monk of the Convent of St. Saba," or St. Sinai. It is only in the latest MSS. that this Monk John is directly identified with John of Damascus, a somewhat distinguished theologian of the eighth century. He was the only ecclesiastical writer of the name of John to whom the book could be attributed, and scholarship, like Nature herself, abhors a vacuum. And so the book of Barlaam and Joasaph has been included among the works of John of Damascus ever since his editors have collected them together. Yet they have not been without their doubts, and they always felt themselves obliged to defend the inclusion of the book. One of his editors indeed, Lequien, went so far as to exclude it altogether from the authentic works. The whole question has been carefully threshed out by M. Zotenberg in his Notice sur le Livre de Barlaam