When the game was "revived" like a year ago it was recieved with fairly big excitement. The trailer on Youtube arrived to 700k views, a similar number to the "Exploration Trailer" of Xenoblade Chronicles X. That's a lot for a game like this.
Where did all the excitement go? Well, to begin with, Shin Megami Tensei (don't be mistaken with Persona) fanbase is not that big. Fire Emblem community is bigger, but the game don't seem to have that much Fire Emblem on it. Second, the game is too damn japanese. The idol thing went too far for the taste of many people who were excited for the idea of this crossover. Third, Nintendo hasn't talked too much about the game. Not like Xenoblade, who always was getting trailers, information, musical themes... Not with this one.