My red card has been at $1300 for at least a year, which is fine with me since I generally don't spend more than a couple hundred bucks at once there and I don't ever carry a balance.
I've generally always paid the bill before the statement even cuts, but didn't this month. Sure enough, I got a CLI to $1800. I've read in other posts that they seem to only give CLIs when you leave a balance when the statement cuts.
Enjoy your new limit