Wow, that's an awfully big reach to make from one simple statement from a random Konami rep.
1. First party publishers could very well mean Microsoft and Nintendo. It doesn't necessarily guarantee that Kojima will be on stage for Sony's conference. If the information is true though, I'm willing to bet if any conference it will be Sony's since Kojima's pretty much always there. Then there's always the possibility that the Konami rep mispoke. Since he was probably speaking off the record he may have been trying to be intentionally ambiguous where Kojima would be during E3 by making conference plural.
2. Even if he is indeed at Sony's conferene there is nothing pointing toward him talking about MGS: Rising. He could be talking about one of his many unannounced games currently in development or even Castlevania: Lords of Shadow.







