Yeah, I agree with that distinction. This is am important semantic discussion.

But he just changed the name of the thing he wants to get rid of from "pain" to "signal". The signal is still a disorder. The signal is the thing that bothers us.

I think they is saying that if you put your hand on a hot thing, you get a signal. You can also call it pain. But the problem is not an internal problem with your body, but a consequence of your environment. So change your environment or what you are doing and the pain will disappear. Don't try to keep your environment the same and try to change within.

(I don't entirely agree with them, but that's my best summary of their argument).