In order to be able to answer that, doesn't it seem reasonable to first consider all possible relevant passages? If we only look at these things in a vacuum, so to speak, thus only from the perspective of what is recorded in Matthew 24, Mark 13, and Luke 21, what about what is recorded in Luke 17? While I do admit, that on the surface, the fleeing appears to be literal, meaning what is recorded in Matthew 24, therefore, it is is perfectly reasonable to assume first century events are meant, if the text is meant to be taken literally. But, if we consider Luke 17 as well, is that what we should really be concluding about the fleeing in Matthew 24, that is meaning in the first century and involves 70 AD?
Let's bring Luke 17 back into the mix for a moment.
Luke 17:26 And as it was in the days of Noe, so shall it be also in the days of the Son of man.
27 They did eat, they drank, they married wives, they were given in marriage, until the day that Noe entered into the ark, and the flood came, and destroyed them all.
In Matthew 24 most of us, including you, take this to involve what happens to the lost once the coming in Matthew 24:30 has taken place. But what about this in Luke 17?
Luke 17:31 In that day, he which shall be upon the housetop, and his stuff in the house, let him not come down to take it away: and he that is in the field, let him likewise not return back.
32 Remember Lot's wife.
33 Whosoever shall seek to save his life shall lose it; and whosoever shall lose his life shall preserve it.
What would be the purpose of doing that once Christ has bodily returned? This sounds like something one would be doing before He actually returns. Look at verse 33. Where have we heard something along those lines before? How about the following?
Matthew 16:24 Then said Jesus unto his disciples, If any man will come after me, let him deny himself, and take up his cross, and follow me.
25 For whosoever will save his life shall lose it: and whosoever will lose his life for my sake shall find it.
26 For what is a man profited, if he shall gain the whole world, and lose his own soul? or what shall a man give in exchange for his soul?
The context is involving discipleship, something relevant to before He returns in the end of this age, not after He returns. Therefore, Luke 17:33 doesn't fit with after He has returned, which means neither does Luke 17:31, and keeping in mind, in Matthew 24, what is recorded in Luke 17:31 involves the fleeing into the mountains.