Iron Ore in the distribution graph of 21w08a levels [80]  [-16] seems to not be spawning in the noise or carving cave generation and exposing itself much in these levels. I was testing this in survival so I might've just gotten super unlucky but even then I had to fetch Iron down at levels [-16]-[-32] in order to find any in the new Cobbled Deepslate and I found half as much diamond as I did Iron at that level?