For future readers (for the original poster, it’s too late), do not use this method to protect a lost Apple Watch. Instead:
Protect a lost Apple Watch - Apple Support
No passcode? Yikes! I believe the Apple Watch’s content remains intact. And having removed this Apple Watch from your Apple ID means you no longer own the Apple Watch.
From this article:
Check your Apple ID device list to find where you're signed in - Apple Support
”If you set up two-factor authentication for your Apple ID, removing a device will ensure that it can no longer display verification codes. It also won't have access to iCloud and other Apple services, including Find My, until you sign in again with two-factor authentication. The device won't reappear in the list unless you sign in again.”