I'm not sure but this is probably too soon to post on the forums. There were some rules for posting IG stuff on the local sub boards.
How so? Rebellions and the like are announced to everyone on the continent, so it isn't like no one knows about it. The regions changing realms is also announced to all nobles of all realms, so there isn't much that isn't known.
If the information is published island wide through game mechanics, it is fine to post on forum. This is my understanding, Moderator do correct if we are wrong.
Just the message I not sure it is the right one to publish, as the message is to only one specific realm. You can send to all the realms Rulers, that will make it more official I think. Hmmm...