I don't think so. As long as everything connects back to Sora its a-okay. Besides it fits Mickey's letter.three destinies is my favorite till now. but I agree it would give away to much and doesn't fit with the "one sky, one destiny" line in Kairi's letter.
my suggestion would be Kingdom Hearts: Digital Data Decoded or Destiny's Data Decoded. Sound lame, but they tie in with coded.
Spoiler Show
I wanted to tell you immediately. There are memories asleep inside you. Those memory fragments connect to the future. Sora, Riku, Kairi, the truth surrounding the Keyblade, passes through numerous connections, which are inside your hearts. Sora, it all leads to you, and everyone is waiting for you.