Twitter user theprinceofiris noticed what appears to be a new collaboration between Tokyo Mirage Sessions #FE Encore and Persona 5. In the collaboration, it looks like Itsuki will be able to wear the Persona 5 Joker costume. Nothing has been confirmed by Nintendo and Atlus.
(=^・ω・^=) Kuroneko S2 - Ore no Imouto - Steam, MyAnimeList and Twitter - PSN: Gustavo_Valim - Switch FC: 6390-8693-0129 (=^・ω・^=)