I checked the subforum for this suggestion and could not find any mention of it. Sorry if I missed anything.
Sending diplomats to other factions is a great new feature of Rome II. It would be fantastic if AI also utilizes this. I don't know how hard it would be to implement but slaughtering AI diplomats to threaten enemies - or just for fun! - would be hilarious.
I hope we can see this in full release or later.
Othan than that I have to say I really enjoy playing with new features. Thanks for keeping Rome II uptodate and fresh.