new beam old beam question

So I bought a new beam generation 2 yesterday (2 hours for it to connect to the TV and true play doesn't work obviously) I'm going to sell the old beam generation 1 and I've reset it to factory reset. The beam generation one is still showing up however on the Sonos account it was registered to. There doesn't seem to be any way to unregister it. If the new owner sets up this beam isn't it going to think that it's still registered under my account? Thanks very much. I did try googling this but t