It would be really helpful for players to receive a message through in game mail system that explains the new feature added to the game. Example, there’s a lot of confused players wandering around asking about the barracks and can we level troops. As well, it would be useful for this type of message to be sent to future players coming in when it becomes relevent. (eg. when they build their stronghold lvl 10)
Also, a quick message about new in game features. For example, people are only really learning about the new alliance recruitment chat now, and apparently it was released about 2 weeks ago!