As of now I don't personally believe this will make enemies necessarly stronger as you reach past 81, but one thing bothers me: The werewolf transformation.
If level 81 was the previous cap and the werewolf attacks are based on level - plus we don't know how high of a level we can achieve under these circumstances, will the werewolf damage be given a ceiling, or can we expect dedicated (and insane) promoting of skills will lead to walking beasts of carnage?