I have heard about many signs over the years even many in the first century believed the time would happen before they died. What you mention very well might be another real sign. My point is there are probably many and how far they are spaced apart nobody knows. Years ago my cousin handed me a 5 page paper on a group that had a leader who figured it all out and told his people he had a date. I read less than the first page and saw it was based on unsound doctrine. The folks in this religious group gave their houses away, cleared out their bank accounts and gave the money to people on the street. They told their boss what he could do and then sat together on the floor of the church when that day came waiting for the hour. I was a young guy at this time so this was many years ago.
I sympathize. I spent a good amount of time in the late 70s writing Chuck Smith of Calvary Chapels fame, disagreeing with his constant claim that Christ could come at any moment, and would precede the reign of Antichrist. He basically ignored me up until the point he suggested I not come to his church--I lived in Santa Ana, CA at the time--not far from his church.
I moved out of state not long after this, and later learned that he began to predict Christ's Return sometime in the early 1980s--something like that. He apparently encouraged people to let go of their material things in preparation for that event. Obviously, it was bad guidance.
Some of this seems supported by the "birth pains" signs that Jesus said would precede his Coming. But he was talking primarily about the judgment to befall his own generation in 70 AD. All of those signs took place at that time.
What are signs that we are in the last generation? It has nothing to do with the Olivet Discourse or with the "birth pain" signs. Rather, it has to do with the rise of Antichrist, in accord with Dan 7. Paul explicitly said Antichrist's rise must precede Christ's return for his Church. Christ would only come to defeat the Antichrist, and not before.
We prepare for Christ's Coming today by living righteously, and not by guessing what day or year he will come. If we live in righteousness, we are ready--period! The prophecy of Antichrist was given to the Church throughout history to notify them that before Christ returns we will have to confront various antichrists, and in the end, the Antichrist himself.
This warning is given to encourage us to avoid deceptions that make us unready. Deceptions can lead us to lead a profligate life, a carnal or corrupt life. By avoiding deceptions and choosing to live a spiritual life we are ready. And this is what we are encouraged to do.