I don't know about them, but Discover didn't send me any confirmation email that I was approved. I can't recall if they sent me an email about the shipped card days later, but I was definitely left in limbo after the online approval.
I don't quite remember when the first CLI is but after the first it will be exactly every 4 months and 1 day. It doesn't change.
My SL was $2,500 about 11 months ago. I am now at $4,900. The first CLI is 6 months and a day. Every other one after that is 4 months and a day - to my understanding.