Imaro
Legend
It's funny, because after reading that rule (monsters are aware of power effects), I never assumed the information had to be used to by the monster. I simply saw it as a DM empowerment tool to ensure that there weren't arguments at the table where players would try to "surprise" the DM with power effects, and feel entitled to keep that information a secret.
I always assumed the DM would filter that information through the NPC's personality and intelligence.
And I would argue RAW you are wrong for assuming that. 4e terminology is very precise and they state that the creature, not the DM and/or player was aware of any effect placed on it. That is clearly character as opposed to player knowledge. Or are you arguing creature is used in 4e to refer to players and DM?