On premise AD migration to AWS Managed Microsoft AD

Short answer is no. One thing to realize is that the managed AD in AWS has specific use cases and isn't meant to be a replacement of your AD that sits onprem: https://docs.aws.amazon.com/directoryservice/latest/admin-guide/ms_ad_use_cases.html

You can't just go into managed AD and start promoting DCs and extending the schema - you won't have those privileges. indeed that's why it's managed by AWS and you have a delegated privileged account with which you can work that has limited permissions.

What I would recommend is setting up a managed AD in AWS and orienting yourself and you will quickly realize what you can't and can do. My clients mainly use it to create a one way trust back on the on-prem AD to provide SSO for workspaces and other services such as RDS.