"Final Fantasy XIV is built on Square Enix's Crystal Tools engine, the
same engine used for Final Fantasy XIII and Dragon Quest X."

You guys might want to look into this. The Crystal Tools was used in FFXIV ver 1.0 but I'm certain they're using a different engine for 2.0 and up.

Sort of, yes. The production for ARR used effectively a hybrid of a then scaled down version of Luminous Studio and existing Crystal Tools engine, which was their first WIP for the Luminous Engine proper. They couldn't use the engine in full mainly as it was still in development at the time and also partly because of the different requirements for XIV vs XV (namely, the multiplayer aspect). First official use of what became Luminous Engine was for Final Fantasy XV.

As to why I called it Crystal Tools at the top of the article, Square Enix themselves haven't adjusted the title of game engine from Crystal Tools in press media packs, that's part of why I inclined to stick with that in the article itself. Honestly though, with some of the improvements they made in Stormblood I'm more inclined to believe that they're trying to bring their engine closer to the main branch of Luminous.

Hope that explains things a bit more!

Thanks for pointing that out!