See post #3. That was a major indicator that the clock started up again. Same generation that sees this, sees “the end”.
No, the same generation Jesus was talking to would see the end. This is the same thing He said in the first and last verse of Revelation “He who testifies to these thins says, ‘Yes, I am coming soon.’” . You cannot read the Letters of the early church without realizing that they expected the “end of time” before they died - and so it was.