I'd say I'm probably more positive on Kingdom Hearts III than a lot of fans, because its fanservice genuinely hits for me. Re:Mind is essentially just more fanservice, and adding stuff that probably should have just been in the game to begin with. In a way, adding everything that once was Final Mix content into a DLC sounds like an improvement for Kingdom Hearts, but here it might be a detriment. The new content isn't integrated directly into the game, and instead is in its own menu with its own saves. It totally limits how much of a game changer the content can really be, especially in comparison to II's Final Mix. All in all, it doesn't feel strictly necessary, nor does it really change my opinion on Kingdom Hearts III.