It's really just for the purpose of humor. You can tell by the way they framed it as a museum piece, used a museum-style description, and specifically called it "Jin's yeeted water bottle."
I don't think it's all that creepy. It's just a fun, personal keepsake from a concert. It's not like they took it out of the trash after he disposed of it.
You're right, doing it for a joke makes a lot more sense