I never understood the necessity for the perpetual virginity doctrine, or why Christian scholars would even find it necessary to discuss such matters about Mary (or any other saintly woman). Before someone gets the wrong idea, I do understand the necessity of the virgin birth doctrine.
Many ancients thought virginity virtuous and having sex evil. That idea crept into the church, and they had to find a way to keep Mary a virgin, even though all the evidence was to the contrary.
Apparently the author of this article doesn’t consider the Gospels to be ‘historical evidence’, although it was written by folks who had probably talked to Mary.