It's kinda funny... I love Persona 5 and the Persona series as a whole (2IS and 3 are great, and 4 Golden takes the cake as one of my all time favorites), but when Joker was revealed I felt this strange... ambivalence? Mild disappointment? I dunno, it was weird. It certainly didn't help that I was in a relatively sour mood given the blackout my neighborhood was in during the livestream, which subsequently cut out the internet, forcing me to watch the livestream on data (Probably shoulda just stopped, but I wanted to catch any cool reveals live).
I guess my reaction was basically... "huh?" Joker being in Smash Bros wasn't even a blip on my radar, and yet, there he was. Much as I like the dude, he was another "anime pretty boy" with a blade, an aesthetic that I'm a bit weary of in Smash. And him making my most wanted, Bandana Dee significantly less likely, sort of dealt a blow to my potential hype for him.
That said, I've warmed up to him since his release (in no small part thanks to that jamming remix of I'll Face Myself alongside the inclusion of Reach Out to the Truth and the Yu Costume). I still dion't love his inclusion, but I do like him well enough. Funny thing is despite completing Persona 4 Golden three times and not even getting halfway through my P5 New Game+, Joker's inclusion just made me want to play P4G again, haha.