Cuphead PS4 is mentioned in some listings of the PlayStation Store itself
Report: Cuphead PS4 Version Spotted on PSN Store - MP1st
Cuphead PlayStation 4 listing appears on the PlayStation Store [Update] - Neowin
Wario64 on Twitter: "Cuphead may be coming to PS4, it's appearing on international PSN stores right now but game listing doesn't load yet https://t.co/ME7oRLkSEM" / Twitter