When I updated my world from 1.16 to 1.19, when I started looking for the new deep dark biome, it did not generate correctly, showing a lack of sculk blocks, skulk sensors, sculk catalyst and sculk shrieker.

I will clarify that:

1. The ancient cities do generate, but not the shulk blocks that belong to the deep dark.
2. This happens when you have an old world generation like 1.16, which has everything above y=0 as already generated previously, but everything below y=0 is generated in 1.19
3. The new terrain generated in a virgin 1.19 world doesn't have this problem