Does this apply only for AWS account sellers?
For the time being, yes.
What about other cloud account sellers?
I've thought about this, and the main reason I'll focus on AWS is because it's by far the more popular one. So far what I've seen is that if a seller is advertising MS Azure or Google Cloud, he's also advertising AWS.
What about people who sell online banking accounts with other people docs?
What about people who sell gamling accounts with other people docs?
Those are obviously a hacked accounts, which are already forbidden by forum rules.