I sold my apple watch and erased all items from it before selling. I also removed the device from my iCloud. I did not unpair it. The buyer states that it is still linked to my email address.
Apple Watch
I quote from https://support.apple.com/HT201441
To remove Activation Lock from a device that isn’t in your possession, follow the steps below. If you purchased a device that's protected by Activation Lock, ask the previous owner to follow these steps.
From a web browser, sign in to iCloud.com with your Apple ID.
To start the setup process, restart the device.
I quote from https://support.apple.com/HT201441
To remove Activation Lock from a device that isn’t in your possession, follow the steps below. If you purchased a device that's protected by Activation Lock, ask the previous owner to follow these steps.
From a web browser, sign in to iCloud.com with your Apple ID.
To start the setup process, restart the device.
How do I unlink an apple watch that I sold, but didn't unpair
