So... Ignoring the fact that there has already been Zelda games with multiplayer, and Deus Ex had one as well...
Not really selling me on any of these. We already got Skyrim Online by way of ESO, and while it has some popularity, without mods the game ends up feeling bland several hours in when you realize the best part of any Bethesda game isn't the world, it's the modding potential. As for the others? Other games have already done them better, Alien had "Alien vs Predator", then you have games like Splinter Cells merc versus agent styled asymmetrical gameplay that fits into the Batman/thief idea...
Yeah... And that is also ignoring the fact that multiplayer isn't intrinsically "deserved". Persona is an amazing game, doesn't mean it deserves multiplayer... Far from it, multiplayer being tacked onto a game is more a sign of laziness or lack of "stickiness" for the single player component.