R&R, as you saw above, I agree with you that the events described in the Olivet Discourse (up to the parable of the fig tree and "this generation") are referring to events in the 1st century. And it is not just the WT who claim that those events have a more future fulfillment. But the surrounding context definitely places them in the events of the Jewish-Roman War of 66-73 CE.
But having said that, look at a comparison of foretold events that Rev 16 describes laid side-by-side with Mt 24 & Lk 21 here. There are obvious similarities, and a few differences also. One could understand some thinking that the Olivet prophecy and Rev 16 are describing the same thing. They aren't. But they are similar enough to lead some to think they are.
It appears that both follow a similar pattern. Yet they each have differences because one is a local event and the other is a world wide event.