Xbox Series X Warranty Transfer

Yes as it's linked o the serial number you should unregister it from your account so the next person can register it under theirs

Unless you have MS complete then you need MS store support agent

Hi ValueUnknown, I hope you're doing great out there despite the issue that you're experiencing. I am an Independent advisor and I am here to help you in regards to your concern.

The Microsoft Limited Warranty is on the device itself, so yes. It will be transferred to the new user.

Not really...

Xbox Series X games / upgrades / updates has to be installed onto the Series X internal or expansion card SSD,

You can have Xbox One games on your external hard drive that will get an Series X upgrade but the games will need to be transferred to the Series X and then the Series X upgrade will need to be downloaded onto the Series X SSD,

As an example...

I have Marvel Avengers on my external hard drive that will get the Series X upgrade and I will transfer the game over to the Series X SSD ready to download and update the game to the Series X version when available.

It says the Xbox Series X has a warranty what do I do with it?

Thanks for letting me know. Kindly try doing a Network Transfer to transfer the game to your Xbox Series X and since it is optimized for Xbox Series XIS, make sure it is downloaded to your internal storage.