TD
In terms of the Olivet (discourse) having a FULfillment (in the absolute definition of the word), the wts teaches that it does. One argument in support that wts uses that is convincing, is that, although the GT in 70 CE was the greatest in the history of Jerusalem, "it is not a greater tribulation than the global Flood in Noah’s day", so 70, is not the only way of applying the prophetic part of the Olivet discourse.
In plain English, the wts teaches, that 70 AD did not fulfill the GT part of the prophecy, because it was not the tribulation described: "great tribulation such as has not occurred since the world’s beginning until now, no, nor will occur again. "