The front page of the "Through the Ages - A New Story of Civilization" Code of Laws says, at the end of the game:
All Age III events in the current and next events deck are evaluated in any order.
Having not yet played a full game, I haven't had it happen, but it certainly seems possible that there might be Age II (or earlier?) events in the current (or next) event decks at the end of the game. Are those evaluated too? It seems strange that you would skip over those, but is that the intent?
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.
I've not got rules to hand but in the original game this was the case. All the age III events were "impact of....." and gave bonus points. Any events from age II or I if still in the event deck would be things that only mattered during the game and not needed to be evaluated at the end.
edit - I'll try and explain this a bit better with a dash of theme! Yes you are correct, it is possible that age II events mights still be in either event deck, but they do not need evaluating. They are just things that thematically never happened. A Colony that maintained independence, a crime wave that never happened, no economic progress, wonders never ravaged.
Many of these age II cards will not affect scoring. Only a few will effect scoring directly and some might do if impact of Colonies has been played for example. once the game is over most the effects, Such as gaining food or resources, won't be a factor.
The end of the game bonus points represent the 'Impact of...' things on the world. Not what is seeded to happen in the future as in game terms that future never got around to happening.
