I doubt it. I got my AOR 10 days ago. It is still CAN000XXXXXXXX. For me as well as wife.If you’ve provided your old details, your UCI will revert to the same old one (8 or 10 digit) once you get AOR. These CANXXXX formats are for EE only.
In fact I don't remember this earlier but I just checked my profile again right now. And it seems that now both my daughters also have a UCI assigned to them. I certainly don't remember them being assigned a UCI earlier (I remember me and my wife getting it). They are 3 and 1 years old respectively.
So yeah, it actually hasn't changed back at all.