Hello,
According to RDS CAL version compatibility, RDS CAL does not support upward compatibility with new versions of Windows Server.
Therefore, the RDS 2019 CAL cannot be used to deploy the upgraded Windows Server 2022, and you will need to purchase the corresponding RDS 2022 CAL.
It is worth mentioning that the RDS CAL is backward compatible, which means that you can downgrade the RDS 2022 CAL to deploy Windows Server 2019 if you need it.
I hope this helps.
Best regards
Jacen