In the new issue of Persona magazine, series director Katsura Hashino spoke about the sort of challenges Persona 5 would tackle.
When asked about the image of chairs with chains, Hashino said "they're at a dead end, chained down to a world of which they resent being a part. Persona 5, in that sense, is a game about freedom, the kind that those sorts of people haven’t had living in the real world.”
Hashino hasn't specified what freedom is being taken away, though it seems quality of life is plausible. Players will be responsible for purging people of this imprisonment. "The characters in this game, through sheer force of will, are out to destroy that which suffocates people in today’s society and, again, keeps them chained down in place."
Still no word on whether Persona 5 will have any connection to 3 or 4, but with the upcoming sequel to Persona 4: Arena, it's still quite possible.
Persona 5 is coming to PlayStation 3 in Japan next winter. Still no word on a North America release, but you can bet it will be coming soon.