According to Pro Wrestling Sheet, Jericho and NJPW had a deal in place since August for Jericho to make an appearance at Wrestle Kingdom 12.
WWE might have also played a role in this decision since Jericho contacted them to lend some NXT stars for his boat cruise and they rejected it because they refused to work with NJPW and ROH and also for Jericho's idea in general for a cruise.
http://www.prowrestlingsheet.com/chr.../#.WgCJk91mPIU
In regards to Ibushi-Omega, rumor going around the net is NJPW wants the match to occur at the next US event for the company.