When I checked yesterday, it showed "sold by: Elegoo Official, shipped by: Amazon"

The Amazon listing is literally an option on the standard Saturn page, so, it has to have been added by the Elegoo account.

Either someone with Elegoo's Amazon account added it, or Amazon has a serious security vulnerability.

Edit: here's a link to the Amazon USA page: https://www.amazon.com/ELEGOO-Monochrome-Reducing-Protector-8-6x4-8x9-8/dp/B0BBF1PBSW?th=1&psc=1