Removing Icloud Account from old phone
Removing your iCloud account from the iPhone 6S from icloud.com or any other Apple device on Find My will mean that your iCloud account has been removed. Was Find My iPhone enabled on the iPhone 6S? If it was, then that means that the iCloud account was automatically removed when erasing the device (your device should have prompted for your Apple ID and Password). If you still have access to the iPhone 6S and want to make sure that it is removed completely, you should probably set up the phone again and use your Apple ID. Then, remove it from Settings &gt; Your Name &gt; Sign Out (at the bottom) and erase the device (Settings &gt; General &gt; Reset &gt; Erase All Content and Settings).