I received an email from AWS entitled "Update Root User Email Address for AWS Account". I'm trying to understand what it's actually asking me to do. The complete body of the email is below.
Is it saying that I'm using the same email address for AWS (the cloud platform) and Amazon.com (the store) and that I need to change the email address in AWS to something different?
You are receiving this message because we have identified that you are currently using the same email address for this AWS account (as listed in the Subject line) and for additional AWS account(s), which are associated with your Amazon.com account. We strongly recommend that you update the root user email address  for this AWS account as soon as possible to separate access to your additional AWS account(s) linked to your Amazon.com account. If you do not take any action by April 10, 2023, we will require you to update your email before accessing this AWS account when you sign in next to your account.
After you have changed the root user email address for this account, you will be able to use it to access your account. At that point, we can finish separating your additional AWS account(s) from your Amazon.com account.
The following are your additional AWS account(s) linked to your Amazon.com account:
After you receive a confirmation email from email@example.com, you can then sign in with the existing root email address for the additional AWS Account(s) and access new features. This can include enhancing the security of your sign-in experience with other Multi-Factor Authentication (MFA) device types, including hardware security keys , and monitoring root user activity through AWS CloudTrail .
Yes, you are right, the request is to use another email for your AWS account.
The recommendation is to separate your amazon.com user from any AWS accounts. For eg: You may have an amazon.com user account for shopping, prime etc. But when it comes to AWS, it serves better to have a different email. This gives you an advantage from a security perspective i.e AWS accounts users do not automatically get access to amazon.com services.
If you have multiple AWS account, there is also a concept of using an organization to bring everything together. https://aws.amazon.com/organizations/