Set in stone? No sir.
I was approved for a Citi DC in October with a measly 700 limit. Still used the cars frequently, but I hated the limit. I knew the rule...but I got impatient. I decided to pull the trigger at the end of February. Soft pull approval for a 1200 increase. I saw I could ask for more at the expense of a hard pull. I decided to risk it and asked for 1100 more. The website stated they will email me their decision. 2 hours later I received that email. Approved. 700 to 3000 in less than six months.
So it can happen. I know it doesn't and won't happen for everybody, but it isn't an ironclad rule.
