In a recent interview, Hayley Joel Osment comments that he hopes to return in Kingdom Hearts III to voice Sora.
Here’s what Osment said to Zap2it:
I saw the announcement and then talked with them a little on the phone. I started doing ‘Kingdom Hearts’ in 2001, and we’ve done the main series and then the Game Boy one. I feel like I’ve done seven or eight installments, which is awesome but with this, they’re making it now and the recording of the dialogue is one of the last parts of the process. Probably this summer or later
Here’s what he said about voicing Sora:
Sora goes back to being a child or goes to another universe or changes into somebody else so I can never say for sure, but hopefully I’ll be back.
It’s very likely Square Enix is still developing Kingdom Hearts III so Osment might not be called up to voice Sora again until the game is nearly finished.
Square Enix did mention last year that Kingdom Hearts III is very early in development and they plan on releasing Final Fantasy XV first. It’s likely the game won’t be out until 2015 if Final Fantasy XV were to come out later this year.