Carey has left due to differences with the management, which is JLT's management. But Carey has a record of being difficult in band situations.
The whole concept of this could have led to disastrous results. It's like Billy Preston, Klaus Voormann and the son of John Lennon forming a band and calling themselves "Over the Beatles". But, miraculously, I've only heard good things about their performances (the obvious JLT haters aside) and, yes, I'd watch them if they dropped by in Germany (and I usaully avoud tribute bands).
JLT, for all his sometimes embarrassing behavior, is a very good AOR singer and able to adapt to songs Gillan, Coverdale, Dio and Bonnet have sung, which is not mean feat. He still sounds like JLT on each of them (or Lou Gramm ...
).
Never much of a fan of Rondinelli's drumming, but he can entertain. Greg Smith has indeed a fine voice, I already noticed that when he toured with the last (real) Rainbow line-up. And young Jürgen Blackmore did ask (and received) his dad's ok to do this.
But why does he have to play a Jackson of all brands?