Possibly you can provide some evidence that early copies of the verses we’re discussing can be translated as something other than “generation” as we normally use it.
I just did.
The Aramaic is the oldest of ALL manuscripts. It's not a translation.
If that's not good enough, then there's nothing more to say. Really, do I need to draw pictures?
Israel hasn't been a nation for thousands of years. How much more needs to be said that He was speaking of the future? 2520 years. 1948 was exactly 2520 years.
And as far as the Greek goes...Just because the oldest ones they found a couple hundred years ago were in Greek doesn't mean they spoke Greek. Very few scholars today believe Greek was the primary language anymore. It is filled with references to Hebrew and Aramaic. It's almost laughable to think they wrote it in Greek. The Disciples were fishermen for the most part. The only writers that could speak Greek were Paul and Luke. Paul studied under Gamliel, the only Rabbi of that period that was allowed to teach his students Greek. He was also the greatest Rabbi of the time. Greek was considered a bastard tongue. Jews, for the most part, didn't speak it. Gamliel was allowed to do so because the Jews saw the need for at least some to speak it.
The official church, and I use that term loosely, for hundreds of years was the RCC. They were Romans. They spoke Greek. No surprise that all of the early church writings were in Greek. They killed all of the early Jewish believers and destroyed anything that remotely smelled Jewish.