Has Squeenix (or anyone) ever "officially" localized an old rom of a text-heavy RPG?
Does Mother/Earthbound Beginnings count?
(I'm not clear if they used the translation from way, way back or if they put it back through in a new patch.)
Localizing remakes are a hell of a lot easier/cheaper than editing a ROM file.
For a big company that doesn't do this much and that has to answer for any of the bugs introduced in modifying the ROM, sure.
But at this point, with the tools out there and the fact that it has to include an emulation layer no matter what (they're not pressing a cart with this), I'm not sure why Square as a business would be afraid/incapable of doing what hackers do on a regular basis? It is veritably not an impossible task. Other companies have already edited ROMs they sell (Nintendo has modified N64 titles, maybe others, to remove sponsored graphics, though I'm not sure if text changes have been done in a sold eShop or PSN or Steam game ROM? Also, those MultiArcade cabinets they sell with licensed boards often have modified elements in them, but those are little title-screen tweaks for rights management.) The ramifications of selling a modified ROM may deter Square Enix (and just generally the prospect of selling IP it has not invested in for a while, though translating this ROM would let them consider it for sale outside of Switch as well, and SoM has been on mobile for a while,) but that seems like the roadblock isn't anything but QA, and QA can be budgeted.