Macbook trade in got cancelled and the device came back?

I ordered a new macbook in Feb and I sent my old device on time (within 2 weeks) But it came back like 3 days ago (2 weeks after I sent it) and it wasn't even a return due to wrong address or something. It had a new sticker with my name as the person to receive and the box was also new.

I'm a bit confused for the reasoning for this return because i didn't get any further notice. My old macbook was a Air 2020.