Ok the one thing about remind that I call BS on, and considering that this is KH that’s pretty impressive, is that Riku, Kairi, and Presumably Sora, don’t look any older after a year when the last time they were apart for a year? Everyone looked different (KH1 to 2), Kairi’s hair isn’t even longer despite being sleep for a year!!
This is Ventus, age 16, Aqua, age 18, and Terra, age 20.
Four years earlier, Xehanort has ripped Vanitas out of Ven’s heart forcefully and Sora has mended Ven’s heart.
This is Ventus, age 12, Terra, age 16, and Aqua, age 14.
They just didn’t make separate models. Sure, you can argue this was for the PSP and it shouldn’t be a problem for the PS4, but this is just a DLC. Nobody knows if the characters will stay the same in the next game or if they will get an design overhaul once more. An anon even suggested that Kairi is in a timeless sleep, similar to Ventus, so she and Sora stay the same age (with Riku apparently aging?).
You also have to remember that the Destiny trio already changed a lot physically. Riku very well could be 17 or even 18. Sora and Kairi look quite younger than him, to be honest, but they’ve always had softer features and still matured a lot compared to their old designs.
Whatever Nomura plans to do with them, their look in the Re:Mind DLC isn’t the be all-end all. I will admit that Sora’s model seemingly underwent changes for the secret episode, but that might be messing with the engine and how powerful it is and how to get the effects the team wants with Versus the next KH title.