I can thin of several reasons.
SOmeone wanted to proposed to their swwetie.
It was used in filming an ad/movie scene.
In either case, tt cost more to remove the piano (union labor!) than the piano is worth.
Hope the cops donate it to a local school or civic orgniation that could use it.
Until the rental company shows up looking for it.
My guess would be a film shoot too, but that’s one ugly-ass, elementary school chump change POS piano if the above picture is related to the story. I’d throw it in the woods too.