Like I said, with the rumor of SCE helping funding and making (and possibly marketing the game with Atlus),I don't really see the game being on PC happening.
Second, the developers you named in that post just happened to make most of the super niche games, with Compile Hearts being a studio under Idea Factory and Acquire being under GungHo (which happens to make most of its money from mobile and MMO games, which happens to have PC as a main platform). The problems with their games from being super niche is they are too weird for the regular market of gamers and JRPG fans in general. Despite the popularity of the systems they release their games on (DS, PSP, PS3, etc), they don't and will never have a bigger market than what they already have. After reviewing their financial situation, you could easily figure that releasing some of their games on PC (via Steam) could cope a bit for that publishing cost affiliated with Japanese games.
Furthermore, if you also take into account that, despite looking like "niche" games, the Persona franchise (and to some extent the Shin Megami Tensei franchise) are "hardcore" JRPGs at heart, which has a much much larger market available to them and that already makes them way more appealing to the regular market and JRPG fans alike. The main attraction with the Persona franchise is the idea of Murder/Mystery/Cult/Demons fused to a JRPG, which already makes it more appealing than the Final Fantasy franchise for a lot of people. The only advantage Square used to have for their games is the marketing power they bring for their big titles, but based on the impressions and reactions to the latest Persona 5 trailer, more people seem to be hyped for this game than FF XV.