You forgot what Kitase and Nomura dont like each other. I only see one of them leaving( in 10 or so years) and this is not Nomura.
There are no indicators of him being unhappy with all these recent events. Actually judging by his latest interviews and the video report about the company he made himself for DKSigma event, it seems to me he is pretty happy with how things are going. Maybe he even wants Kitase to leave, who knows?
But anyway, there is one thing I've learned during the last 5 years: Gaming industry is not like Movie industry - creators names dont matter here. Sakaguchi and Matsuno pretty much proved that to me.