I am not sure this would be in agreement with these policies, or at least the spirit of them: https://aws.amazon.com/security/penetration-testing/
"Kid Tested. Mother Approved."
Kids tested it but we don't know if they approved it. We don't know if mothers tested it; we only know they approved it.
When the source says they already did their due diligence...
I agree that the account number just by itself is not a secret, but there is a reason why all AWS demo videos mask the account number.