Yeah, I thought of when I first followed overclocking in the late 90s, and Intel had a reputation for selling artificially slow chips in those circles. But in that case rating the appropriate clock is a subjective exercise, and they don't want the part to start failing if pushed to its limits. GP here made it sound like it was rather more harmless in this case, not sure if that is a mistaken impression of mine or what.

Unless demand for the less expensive part exceeds the defect rate.

AMD CPUs, especially the 3-core parts, were often unlockable by re-enabling the disabled cores in BIOS. Lucky buyers could get 4 cores for the price of 3.