Recently I followed the on-device steps for resetting my iPhone and preparing to give it to someone else. But after completing the process, my iPhone still appears in the list of devices associated with my account. Why? Is there an essential step that isn't included in the on-device walkthrough? Years ago, before the on-device process was implemented it used to be necessary to start by signing out of iCloud on the old device. But this is not mentioned in the walkthrough, which in any case says that iCloud will be disabled.
Is the sign out step still necessary even though it isn't part of the on-device process of wiping a phone? If so, what should I do now that I've wiped my old phone already without signing out of iCloud?