I'm with you, if you're going to make all this noise about going for it, then you should be willing make tough decisions that you might be loathe to make if it's the best option to win, which bringing up Zadorov is. I don't know what their rational is - my best guess being they don't want to bring him up to play very limited minutes and mess with his development in SA where he's a minutes eater, but regardless whatever the thinking is I think it's the wrong decision.
I'm just not surprised that they're not willing to be honest in their reasoning publicly, as nice as it would be to see some transparency there.