I don't know what you mean by time period. However, it is theorized that since the Bone Carver claimed to be an old god from another world that he is one of the gods Aelin kicked out of the TOG world so more recent than TOG. But that's all I've got on that.
I completely agree! I feel like Mor should just tell them already. It's been 500 years and of course they're going to accept her or else Feyre will burn them or something. But I hope when she does tell them, Azriel accepts it and gets together with Elain cuz I live for Elriel.