This should be something added to an AWS Security Hub check, e.g. do you have Route53 pointed to an unregistered domain. Otherwise, I can't find fault with AWS at all. Now I have to review our domains on Monday.
Please bug your TAM if you have one about this. I’ve bugged ours. S3 should not serve a bucket as a website without domain verification. In the interim, we’ve built middleware where a bucket serving content can’t be removed until the dns record has been.
The point is that without domain verification, it won't stop someone else from registering that bucket (which is what happened with the domains in this article).
The point is that S3 isn't a CDN. If you use it as a CDN, it's on you to ensure it'll work for your use case. CloudFront, however, is a CDN, and as expected, has domain verification.