J means by making a big scene and posting that he was leaving. Most people who have the intention of leaving just leave without a word. It's like running away from home, you wouldn't tell your parents you're going to do it if you wanted to get away with it. But you tell them you are leaving when you go on vacation and expect to return, right?
I wouldn't mind having Thelis back at all; He gave a little spice around here. But it wouldn't quite be the same. He didn't leave just because of the avatar thing.