The motivation for Nintendo to buy ports of games like Persona are different than Microsoft's reasoning. Phill Spencer has been given the authority to write big checks to sell Game Pass, even if that means losing money in the short term. He said in the presentation that he wants Xbox owners to know that he wants Japanese games on Xbox so he probably put in a lot of money for one of the most Japanese series out there, Persona.
Nintendo already has Japanese games of course, especially JRPGs. Persona does not offer an experience that is lacking on the system. Nintendo has their own series like Pokemon and Fire Emblem plus a good number of games from Square through their marketing/publishing deals. Then of course the Switch has Atlus' own SMT V. While Nintendo would be happy to have these games, they are probably not going to pay well above their worth just to have them on the system. Persona 5 specifically is popular but it's not THAT popular, at least compared to other series they could go after. Having the games on the system doesn't change the narrative of the system like it does with Xbox.
Nintendo isn't the type of game just spends a ton of money and not expect some immediate return. There's a limit to how much Persona is worth to Nintendo and they are not going to pay above that. This all assumes that the Persona games are not coming to Switch of course. I think there's a change that they do get announced later but any ports would more for the benefit of Sega and Atlus, not Nintendo.