No: was definitely present on iOS 5. In fact, this plagued people during the first week after the 5.0.1 jailbreak release[1] and was later defeated by planetbeing as part of "crazeles"[2].
What a waste. People don't know how to use a jailbreak detection system. One doesn't "plague" people with the information. Doing this actually destroys the value of it. One should never restrict features and functionality based on this.