Hackings show inaccessible areas in Destiny Islands and Dwarf Woodlands in Kingdom Hearts 0.2 Birth by Sleep -A fragmentary passage-

This dives so deep, we can actually see the real destruction of the Island at this point now. It's so sad yet so interesting... It's almost crying "put me back together!"

The last one just seems like they’ve fallen off the map to me

Saw this on TheGamersJoint. Cool stuff.

Ooh, thanks for showing this to us, Neil!

Wow, Destiny Islands looked amazing! I'm impressed with how graphically beautiful it looks, and it just makes me all the more excited for how graphically gorgeous Kingdom Hearts III will be!

It seems as if Destiny Islands was planned to be a playable location with jumping from different fragments of the island, similar to Dwarf Woodlands inside the mirror in 0.2
​It would've been very interesting to investigate the island ourselves and end up heading to the cave rather than having it as a small cutscene after the boss fight. 

They could've added more objectives there to achieve like collecting treasures that are hid between the grasses and fragments of the island with having Water Core heartless appearing form the small lake near the cave. It would've also been also a great place to introduce a new type of pure-blood heartless like Sand Core, that comes out from the sands of the island that are obviously seen in 0.2. Or at least, it would've been a good place for yet another secret boss too