It's not illegal to make publishing deals in any way. And Square isn't beholden to anyone in particular. They have made deals with Nintendo and even Microsoft for various games, promotional material, etc.
And that's not even getting into their game-adjacent deals (AMD, various cloud services) and the dozens of crossovers with the stragest companies (remember when Final Fantasy 13 released some Louis Vuitton fashion line?)
And that's not even getting into their game-adjacent deals (AMD, various cloud services) and the dozens of crossovers with the stragest companies (remember when Final Fantasy 13 released some Louis Vuitton fashion line?)