3DS has a strong RPG audience, it would sell very well on that platform.
Wii U would bring in some sales and welcome the niche crowd next to Fire Emblem X SMT and Xenoblade II.
Wii U. Would definitely cater to the niche crowd alongside FExSMT.
Putting it on a wii u would be a death wish in japan.
I think PS4/PS3/PS VITA would be the best choice, seeing as persona has always been a sony exclusive, and the persona fanbase own sony systems.
The Shin Megami Tensei series for the most part was Sony exclusive until brought over to Nintendo.
They decided to put the series on handhelds, Due to it's sub par sales on the ps2, plus with the handheld surge in japan, it was an obvious choice at the time, Persona doesn't need to change platforms, seeing as it sells well on sony platforms, plus persona 4 the golden managed to outsell shin megami tensei in japan, despite the 3ds having a much larger install base.