It worked that way on Live too though
I played a rogue on live and using escape while something was casting on you would break hide/sneak and also add you back to their hate list. So unless something has changed since I played, I think that would be perfectly acceptable and intended. I am not sure even with changing how IsEngaged works that a spell being cast on you won't cause aggro after you escape or fade. It should at the very least break your hide/sneak.
Maybe you can put those changes back in unless someone else thinks it should work any differently.