He may have expected that adding the Abilify immediately as the Clonidine was ceased would prevent any rebound??? I don't know.
I remember when my son was changed from one atypical to another, they didn't slowly withdraw the first one. They added the 2nd one at very low dose and then ceased the first one pretty much immediately.
What I don't know is how it works with Clonidine when adding a neuroleptic. Know what I mean?
I suffer, and I mean suffer, from panic attacks. The only time in my life when I feel as if I'm not on ALERT

is the times in my life when I've taken drugs like xanax short term. However, I made a decision many, many years ago not to go down that route.
If you trust your Neurologist and he knows you and your son and what's been going on, then go in there with a list of questions for him tomorrow. If I recall it was the ER that prescribed the xanax originally wasn't it? The Neurologist is maybe just waiting out the time to get the Abilify kicked in. Then your son might not need that extra calming that he's getting from the xanax.
Hang in there,
Lara