This assumes the Gospel of Judas is correct. As I said, it does not appear in records until 120, and irrc the extant copy is philologically dated to be later. All of the Canonical Gospels are dated to before 100 AB, with the possible exception of John. In any case, the "silencing" is a result of modern printing methods, apophrycal books were read and studied during the medieval epoch, as were the Letters of the Church Fathers.
Personally, I do not give this conspiracy theory and more credence than the lies the Inquisition spread about the Temple Knights.
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