Cloud was announced for smash in November 12th, 2015. FF7 came to the switch in March 26, 2019.
So by your logic.. Persona 5 for the switch is coming out... in 4 years?
Or is it possible that cloud was added because of the 3ds games he is on and Joker was added because of Persona Q 2?
Snake was also announced for Smash and so far the only MGS game i know came out for Nintendo was a port of the old MGS3 to the 3DS.
Edit: I mean after Snake appeared on Smash (i am very aware of Twin Snakes on the Gamecube).
I thought this was the announcement of the 25 since today is 25 on Japan but i guess i will wait to tomorrow and find out, i must say however that if it is a Switch port its just weird to wait one day to announce it, isnt the persona super live event where it will be announced? if thats the case it wouldnt surprise me if P5S is an improved version of Persona 5 Dancing in the Starlight.