Macbook Pro "Demo -Not for Resale"

I came across something odd and was wondering if anybody has any experiences with these "Demo" models.

A friend of mine recently found a M2 Macbook pro 14" on FBM for a good price - $1500, listed as used but appearing to be in pristine condition in the pics (this same model according to the Item number sticker on the box https://cocoeast.ca/costco-east-electro ... 2579-99-2/ so must have come from Costco). I tagged along for the meetup to help check it out/be an extra person for the transaction. Looked super clean and powered on, warranty shows good until Feb 7, but what caught my eye was the text on the box "Demo - not for resale".

I googled it up and got conflicting info, from "It's likely stolen" to "it uses custom firmware/OS for the demo mode" and "it's locked through MDM", to what I would also assume "Just restore the OS and it will be fine". I wasn't sure what to say and my buddy backed out of the deal (seller would not allow creating an account/password, we got the OOBE setup screen to connect to wifi etc). Now I'm curious, was there anything actually different about these non-saleable demo models?