Chain of Memories Castle Oblivion = Castle of Illusion?

I heard that early concepts had Castle Oblivion actually be a renamed Castle of Illusion that the Organization took over, making the Genesis game canon, but because of issues with Sega it got scrapped...could this be true? There have been lots of "Castle Something"'s in Mickey games.

 

Castle Oblivion is explained in BBS. Though they still haven't explained how they found it.

 

Hum, for what I can remember, Castle Oblivion was, is and will always be Castle Oblivion. After all, even the organization call it CO, so they wouldn't change the name. Castle Oblivion is a Castle where anyone who steps there will be lost to oblivion.

That happened in Birth by Sleep, when

Spoiler

the Land of Departure has driven into Darkness. Eraqus asked Aqua that, if that happens, she should take his keyblade and lock that land. In this way, the land will be preserved, and anyone will ever be able to solve CO's mysteries, except Aqua.

 

Castle Oblivion is always Castle Oblivion. Maybe the Organization came up with it though. After all,

Spoiler

we know that Aqua never called it Castle Oblivion, and Eraqus did say that it was still Land of Departure; just hidden by that "trick".

It might be that Organization XIII called it that because they could never get what they wanted. However, looking at the definition of oblivion it might be something different.
Definition: a state of complete forgetfulness or unawareness
And after all, Sora did lose his memories in that place. Although that might have to do with Namine, so maybe they named it that because of her. But the members were also unaware of the true nature of the castle, so there is that

 

Maybe they based the castle on it but no Castle Oblivion isnt the Castle of Illusion.