This section on HSM is missing in my opinion, a description on how HSM integrates with the AWS services.
I digged into it and found that HSM integrates through KMS using Custom key stores.
Hi Daniel, you are right. AWS announced new integration features during reInvent 2018. This video explains new integration here . I will suggest you watch reInvet 2017 security videos and reInvent 2018 security videos as a part of preparation for Security Specialty exam.