I think I remember that Paul mentioned in one of the live-streams that the age now depends on your researched techs. The first age takes only 10 techs to complete, the age of war 100 techs and the age of ascension needs 250 techs. Depending on your game style, it will take more or less time to complete an age.

That's said, the original mention sounds definetly like a bug to me, especially available techs that you actually should be able to use (I don't know if it is implemented, but it definetelly should block use of techs that you do not have the preceding one(s)). On turn 45 you probably should have enough technologies, especially if you bought a bunch from the AI, to ascend to the age of war.