I thought that Death Note was much, much darker than D.Gray-man, it being a psychological thriller with much more graphic and rampant death and all that kinda messes with your head while DGM is still obviously in a sort of fantasy realm. Besides that, other things that have much heavier dark and religious tones have already been dubbed and not really censored... like Hellsing comes to mind.

I don't see why they'd remove or change much at all, or decide not to do DGM because of it's themes when there's already much worse. It's not like DGM is targeted to children.