Dreamhost use the word ‘account’ in two different ways,
(1) refers to a login id/password to the panel (which I think you cannot cancel except by asking Support)
(2) refers to a hosting service plan (which you can cancel yourself).
It gets confusing. For example, where in the panel it says “rename account | close account/end all hosting”, the first mention of ‘account’ is in sense 1, and the second mention is in sense 2.
If the second part of the link is not there and it only says “rename account”, this means that you have no hosting service plans.
The simplest thing in that case is just to walk away (having removed your credit card information, and changed your name and address to random data). But if you want to make absolutely sure, then I think you need to ask Dreamhost Support to manually remove your account.
Another potentially confusing aspect is that they keep talking about when you can or cannot get a “refund” (usually available only within the first 97 days of service) but they almost never mention that when you cancel a hosting service plan, the unused balance is re-credited to your account, which you can then spend on something else such as domain registrations before you walk away.