And it’s full width for the first time.

full width doesn't matter. 90% of the AVX512 advantage is 32 registers, masking, and all the other nice features.

We had Ice Lake and Rocket Lake too, they seem to have disappeared from the collective memory

I have an ice lake laptop with avx512. The problem is that intel only made about 15 of them because their 10nm process was a disaster.

Their successors had more tangible performance improvements in everyday applications, so yes they were quickly forgotten. Also, it was a reduction in max core count from 10 to 8, intel changes sockets too often, and 14nm+++++.