Not entirely true. In fact, Square was working with Sony before there was any idea of FFVII. Secret of Mana was supposed to come out for the SNES-CD addon, but due to reason known, the game had to be cut significantly to go on a regular SNES cartridge. There are sources that even say that this very experience is one of the if not the main reason why Square went along with Sony, after they broke off and made their own competing console. Square continued with Nintendo's SNES for a while because.. well.. it was the best selling console in Japan by far.
! I don't think I've heard that particular story before. Interesting bit of history. I'm now reading an article about the SNES-CD.
Chinese food for breakfast