Why are people so hung up on this? Atlus is not a big group and dedicating a ton of resources to developing a for a new console would have been ridiculous for them.
Honestly, if Sony were smart they would coordinate with an outside team and work with Atlus to port the game to the PS4 exclusively. Kinda like they are supposedly doing with Borderlands 2, Iron Galaxy, and Vita. Would totally make sense to do this simultaneously as the game was being localized. There's enough fan outcry that most of the hardcore Persona devotees probably own PS4s making it an automatic buy. Hell, how many people bought Vita's to play Golden. I would totally welcome P5 in Winter 2015 (a year after the initial release) if it were on PS4.
I also think it would look pretty good for Sony if they could claim there would be a PS4 exclusive JRPG (meaning not on Xbox One) for North America in late 2014/early 2015.
Many people have been tweeting the people who say they listen to what the fans want in terms of third part games, so I guess it's something that they could consider if they wanted to do that.
I think the most wanted game there is Yakuza 5. At least that what I remember boyes was saying a while ago. ^^