For some reason this is the first time I'm seeing this interview. And I found it on Gamespot after searching it on google. Still, there are some inconsistencies.
Firstly, it was stated by Nomura himself that KH III wouldn't be the end of Sora's story.
And secondly, it was also stated by him that after KHIII a new saga would begun.
So...unless it is on kh13.com, or I won't believe on it. It sounds too much suspicious too.