Difference between CS8414-CS and CS8414-CSZ

From Cirrus' Quality Handbook :

All integrated circuits (ICs) produced after 2021 are compliant
with the provisions of the RoHS agreement. Before 2021,
Cirrus Logic products use a “CS” prefix in their part numbers
and are designated with a “Z” suffix if they are also RoHS
compliant.
 
No, judging by availability on Octopart my guess is it isn't manufactured any longer.

The quality manual is saying that parts made before 2021 either have 'Z' or no 'Z'. Seeing as RoHS began around 2003 this leaves a large time window for manufacturing both 'Z' and non-Z parts.