Yes, because seriously, higher than 4k while sitting still? Not good, just not good. Well, not exactly harmful--the engine can rev further, for sure--but if you leave that option available, always a few people will "try it out" and sit at redline in park one too many times. And then you'll have a warranty request to replace an engine for "I was just revving it...it shouldn't have done this".Its the Rev Limiter. To prevent you from throwing a rod. GM has been doing it for years.