Do Age II or earlier events happen at the end of the game?
Official Through The Ages: A New Story of Civilization handbook says that at the end of the game:


  Final Scoring
  At the end of the game, take all Age III events
  remaining in the current and future events decks and
  evaluate them one by one. Order is not important.
  
  Note: Events from older ages have no effect on final
  scoring.


So everything is said clearly, events from older ages have no effect, no matter if they could be useful or not in the final summary.

These rules hasn't changed from the previous Through The Ages: A Story of Civilization where the official rulebook was saying:


  At the end of the game, reveal all remaining Age III Event cards from the Current and Future Events decks and score bonus Culture Points according to these cards.


To sum up, if you want any of your previous ages events present in current deck to be evaluated and the game is closing to an end, you have to hurry up with playing new events and hoping that the one you are waiting for will be revealed before the game ends.