Recognizing the obvious fulfillment of prophecy isn’t a new fad. Eusebius (who helped preserve the writings of Irenaeus btw) saw it plain as day in 314 AD:
“And all this prophecy of what would result from their insolence against the Christ has been clearly proved to have taken place after their plot against our Saviour. For it was not before it, but afterward from that day to this that God turned their feasts into mourning, despoiled them of their famous mother-city, and destroyed the holy Temple therein when Titus and Vespasian were Emperors of Rome, so that they could no longer go up to keep their feasts and sacred meetings. I need not say that a famine of hearing the Word of the Lord has overtaken them all, in return for their rejection of the Word of God; since with one voice they refused Him, so He refuses them.” (Eusebius, Demonstratio Evangelica, X)
“When, then, we see what was of old foretold for the nations fulfilled in our day, and when the lamentation and wailing that was predicted for the Jews, and the burning of the Temple and its utter desolation, can also be seen even now to have occurred according to the prediction, surely we must also agree that the King who was prophesied, the Christ of God, has come, since the signs of His coming have been shewn in each instance I have treated to have been clearly fulfilled.” (Demonstratio Evangelica (Proof of the Gospel); BOOK VIII)
“If anyone compares the words of our Saviour with the other accounts of the historian (Josephus) concerning the whole war, how can one fail to wonder, and to admit that the foreknowledge and the prophecy of our Saviour were truly divine and marvelously strange.” (Book III, Ch. VII)
“It is fitting to add to these accounts the true prediction of our Saviour in which he foretold these very events. His words are as follows: “Woe unto them that are with child, and to them that give suck in those days! But pray ye that your flight be not in the winter, neither on the Sabbath day; For there shall be great tribulation, such as was not since the beginning of the world to this time, no, nor ever shall be.” The historian, reckoning the whole number of the slain, says that eleven hundred thousand persons perished by famine and sword, and that the rest of the rioters and robbers, being betrayed by each other after the taking of the city, were slain. But the tallest of the youths and those that were distinguished for beauty were preserved for the triumph. Of the rest of the multitude, those that were over seventeen years of age were sent as prisoners to labor in the works of Egypt, while still more were scattered through the provinces to meet their deaths in the theaters by the sword and by beasts. Those under seventeen years of age were carried away to be sold as slaves, and of these alone, the number reached ninety thousand. These things took place in this manner in the second year of the reign of Vespasian, in accordance with the prophecies of our Lord and Saviour Jesus Christ, who by divine power saw them beforehand as if they were already present, and wept and mourned according to the statement of the holy evangelists, who give the very words which be uttered, when, as if addressing Jerusalem herself, he said: “If thou hadst known, even thou, in this day, the things which belong unto thy peace! But now they are hid from thine eyes. For the days shall come upon thee, that thine enemies shall cast a rampart about thee, and compass thee round, and keep thee in on every side, and shall lay thee and thy children even with the ground.” And then, as if speaking concerning the people, he says, “For there shall be great distress in the land, and wrath upon this people. And they shall fall by the edge of the sword, and shall be led away captive into all nations. And Jerusalem shall be trodden down of the Gentiles, until the times of the Gentiles be fulfilled.” And again: “When ye shall see Jerusalem compassed with armies, then know that the desolation thereof is nigh.” (Book III, Ch. VII)
“And the people of the governor that cometh will destroy the city and the holy place.” Meaning that the city and the Holy Place are not only to be ruined by the leader to come, whom I have identified in my interpretation but also by his people. And you would not be far wrong in saying, too, that the Roman general and his army arc meant by the words before us, where I think the camps of the Roman rulers are meant, who governed the nation from that time, and who destroyed the city of Jerusalem itself, and its ancient venerable Temple. For they were cut off by them as by a flood, and were at once involved in destruction until the war was concluded, so that the prophecy was fulfilled and they suffered utter desolation (400) after their plot against our Saviour, which was followed by their extreme sufferings during the siege. You will find an accurate account of it in the history of Josephus.” (Demonstratio Evangelica (Proof of the Gospel) ; BOOK VIII)