The only real reason there was English in Chrono Trigger is the fact that they were working on a simultaneous US release along with the Japanese version. The Japan and US versions were released literally about a week apart from each other. They translated the game into English as soon as they began making the game and English screens were released almost immediately after the game was announced. Plus it was just a basic port of the SNES game which had already been translated once before.
The only other Japanese game I can think of with English in it was Dragon Quest 4. It was hidden in the code and had to be unlocked via action replay or editing a value in a hex editor. It was heavily glitched, with lines of text being misaligned, some new scenes not translated at all, and other such issues. It was basically just a very early English script said to be ripped straight from the NES game and put hastily into the data. It had several other languages too surprisingly.
No such luck for this KH game. Apart from a plain teaser site launched for the US version, absolutely no information, details, or screens have been released showing the game is even being localized yet. They may not even have begun yet (although they likely have).
