It's only going to damage the IHS, it's not going to damage the CPU or anything like that. 2 years is a stretch though, I've done mine 3 times in my ownership (Nov 2016) and I didn't have my first go at it till 2017 IIRC. Last time I did it the temps were really high and I had hardly used it in a year. If the IHS survives with a lapping then that'll be fine. I was concerned with my heatsink mating face as that would be VERY expensive to replace. The IHS is less to worry about.
Stock IHS is normally nickel plated copper. The Nickel protects it as it's really tough and durable.
Stock IHS is normally nickel plated copper. The Nickel protects it as it's really tough and durable.