Could the book of Revelation be written before AD 70, because there is no mention of the destruction of the Temple?
The dating of the book of Revelation is somewhat speculative, but some of the early church fathers (Clement of Alexandria, Eusebius, Irenaeus, and Victorinus) wrote that the Apostle John experienced exile on the island of Patmos during Domitian's reign (v1:9). They wrote that the government allowed John to return to Ephesus after Emperor Domitian's death in A.D. 96. These things were known in the second century, and we have no historical evidence to contradict that early testimony. Consequently we date the writing of this book to A.D. 95 or 96.
Those who argue for an earlier date do so merely to support their preterist interpretation of prophecy, which does not hold to a literal interpretation of Revelation. Therefore, since they deny a future, worldwide tribulation or 1,000 year kingdom, they teach that the destruction of Jerusalem in AD 70 was the fulfillment of Revelation’s prophecies. Therefore (out of necessity to support their interpretation) they must date this book prior to A.D. 70. This is eisegetical interpretation, which is not valid.
Also, your suggestion that the absence of any mention of the temple destruction in Revelation proves that the book was written prior to AD 70 is making an argument from silence, which is a logical fallacy. The book of Revelation is apocalyptic literature, not a historical work, and therefore we should not expect it to mention any historical context.