Zechariah, Jesus, and the Jews

Recently I read the following conundrum:

A second question that I have concerns Zechariah’s prophecy.  Zechariah seems to talk about Messianic expectations that many Jews of his day had: Israel would be saved from her enemies and serve God without fear (Luke 1:71-74).  Zechariah was excited because he thought that his son John had something to do with that.  But that did not happen.  Rather, Israel’s Roman oppressors destroyed the Jerusalem Temple in 70 C.E.  

http://jamesbradfordpate.blogspot.com/2015/11/struggles-with-luke-1-and-possible.html

Several observations:

i) That poses an interesting dilemma. Critical scholars date Luke to post 70 AD. Typically, they date it to 80-100. But if so, why would it include a prophecy that, on one interpretation, was falsified by the fall of Jerusalem? Indeed, critical scholars don't think this is a real prophecy, or something Zechariah actually said. Rather, they think that's fictional dialogue the narrator put on the lips of a fictional character.

But in that case, something has to give. The date or the interpretation of the oracle.

ii) A prophet is a recipient of information about the future. That, however, doesn't imply that he knows when that prevision will come about. He relays what's been revealed to him, but that doesn't come with a calendar date. A prophet has an instrumental role in that regard.

iii) I wonder if one possible answer isn't to assess this by considering what might have been had the Jewish-Roman wars not occurred. An imaginative exercise in alternate history. 

Certainly those wars were devastating for the Jewish people. But they also forced the survivors to scatter hither and yon.

Had the bulk of Jewry remained concentrated in the Levant, how well would the Jewish people have survived the rise of the Byzantine Empire, followed by the rise of Islam? I believe the Byzantines were fairly hostile to Jews. But on top of that was the military conquest of the Levant by the Muslims. 

To the extent that Jews clustered in that general vicinity, they'd be far more vulnerable to genocide. But because they were dispossessed and dispersed well before then, they didn't present such a compact and inviting target.

Seems to me that this is consistent with how Scripture often views things. A short-term disaster has humanly unforeseen benefits in the long-term. To use a metaphor, it reminds me of:

serotiny (adj. serotinous) In certain plants, especially trees (e.g. jack pine (Pinus banksiana), lodgepole pine (P. contorta), and many species of Eucalyptus), the retention of seeds in pods or cones on the tree, often for many years, until a disaster, most commonly the heat of a fire, causes their release. After fire, the seeds fall on ground fertilized by ash in a site cleared of competitors. 

http://www.encyclopedia.com/topic/serotiny.aspx

iv) Finally, I wrote a NT scholar for his opinion. He wrote back saying:

Actually, with roots in Daniel, the battle here is not just seen against Rome. For Luke the victory is over spiritual forces. Judaism wrestles with a Messiah in two comings where the political victory is later. It does come as Zechariah offers but in two stages. What the OT presented as a single package, the NT has in two steps.