Hmm, there certainly is a lot to be said for
Sauce's plan. Manwe should take care of his own messages for any important diplomatic situation to be sure that there are no misunderstandings...and to prove that he's worthy of staying in this game. If he does come, I can't see the Elves getting into a fight in front of him - it's never good to cause trouble in front of the Boss.

And if Manwe doesn't show up to make a declaration, I have to agree that there's still less chance that the either the Noldor or Teleri will start trouble. Either way, we've avoided a Kinslaying.
And Eonwe has become entirely too conceited since he got this job. All he does is brag about how he was chosen to be Manwe's Herald. It's very annoying.
++EONWE