If you mean in DE specifically it never seems like they have been a strongly common feature no. I remember people commenting on the lack of water on Arabia more than a year ago.To be honest, I do not really remember cliffs and wood lakes before this patch but rarely played so I might be wrong there.
In this one it sounds like you can't quite get away with little Feudal army quite as much anymore but if the woodlines are so regular and safe it reduces the pressure placed on a player by the openness and limits the need for strategic adaptation (as you say, playing Dark Age) that everyone has made quite clear was a hallmark of the classic Arabia.Well, yes. It was always map, where you played all four ages. In DE, you basically skipped feudal. In AoC you could not afford to make some m@a into one range and 18 min up because you would most likely die or suffer casualties due to pressure of feudal army.