Agree that the dating of John’s gospel could not possibly be later than 100AD. In fact, I submit it could not have been written after 70AD. The Roman general Titus in 70AD completely destroyed Jerusalem such that one stone was not standing atop another (Josephus describes this). In chapter 5 of John “there is” a sheep market with 5 porches. Not “there was.” Some people say this is vivid narrative, but that goes out the window because the normal tenses are resumed right afterwards.
I agree completely because IF the gospels (or any of the New Testament) were written after 70 AD, they would have included the destruction of the temple. Why? Simple...Jesus predicted it. The whole point of the book is to try to persuade the reader that Jesus was the Messiah. What better proof than to show a major prediction He made came true? Yet it is completely silent on what was easily the most catastrophic event in Jewish history at the time.