I encountered this glitch too. I'd really like to get Oathkeeper, so is there a way around this? Edit: Yes! I found a workaround: I saved the game, then quit the iso and loaded the untranslated Japan iso. The cutscene played fine. Since the saves transfer between the translated and untranslated versions, I suspect this will also solve the problem of rare heartless not appearing. Edit 2: Yes, it does! Using the original Japanese version, I got all the rare heartless to spawn when they weren't spawning in the translation. Based on the commends, it seems the translation can't support the rare heartless right now.
It worked great! Thank you all!