Hello Sql Kkr,
This situation occurs because the device's unique hardware hash is still registered in the Autopilot deployment service associated with the now-inactive tenant. When the device connects to the network during the Out-of-Box Experience (OOBE), it queries the Autopilot service, identifies the existing profile, and enforces the "Welcome to [Company]" login screen. Since the lock is server-side and tied to the hardware ID, reinstalling Windows or wiping the drive will not remove this restriction; the device will simply re-lock the moment it touches the internet.
Because you do not have Global Admin access to the tenant to manually delete the device hash from the Microsoft Intune or Microsoft Entra admin center, and the tenant itself is inactive, you cannot perform the deregistration yourself. The only official and technically valid solution is to submit a support request to Microsoft to handle the deregistration on the backend. You will need to contact Microsoft Support for Business (often via the Global Customer Service phone numbers if you cannot access a portal) and request a "Device Deregistration" for a device stuck in a defunct tenant.
The support team will strictly require proof of ownership to proceed. You must provide a copy of the original purchase invoice or receipt that explicitly lists the device's serial number and the company name. Once the Data Protection or Intune support team verifies the documentation and confirms the tenant is inaccessible, they can manually suppress or delete the hardware hash from the Autopilot database. Only after they confirm this action is complete should you reset the device again; at that point, the OOBE process will no longer detect the Autopilot profile, allowing you to set it up as a personal device or enroll it in a new tenant.
I hope you've found something useful here. If it helps you get more insight into the issue, it's appreciated to accept the answer. Should you have more questions, feel free to leave a message. Have a nice day!
VP