"Approval emails" from IDPH have been reported by several people in this thread (see, e.g.,
this post), although they all seem to be in response to status inquiries made by the applicants. So while it does not appear that IDPH will send approval emails as a matter of routine, it also appears that some people have indeed gotten emails from IDPH in advance of the receipt of their cards.
I have no idea whether the person you're referring to received an "approval email" or not, but without more facts, it's hardly out of line with other reports in this thread.