The two titles are backed by Nintendo, and only Nintendo can decide to take them to other platforms.
Amidst sudden uncertainty regarding Wii U third party titles resulting from announcements involving 'Ninja Gaiden 3: Razor's Edge' and 'Rayman Legends,' Platinum Games designer Hideki Kamiya has spoken out regarding two popular titles coming from Platinum Games for the Wii U, 'Bayonetta 2' and 'Wonderful 101.' "We are a developer. Nintendo are the ones kind enough to fund and publish our The Wonderful 101 and Bayonetta 2 projects. So if Nintendo says, 'We are publishing Bayonetta 2 on PS3/360,' then it will happen. So please go ask them, not us."
The current turmoil regarding platform exclusivity hearkens back to when Square-Enix announced that 'Final Fantasy XIII' would be on the 360 in addition to the PS3. With the details of such deals kept secret and "exclusive" pronouncements often broken, consumers are becoming increasingly wary, with the most vocal debating the results throughout the internet.
'Bayonetta 2' seems to have drawn a greater interest on account of the exclusivity than if it had been for the 360 and PS3 as the first game was.