Interesting moves. I like the look of that defense - it has a considerable amount of upside to it that our current group doesn't have. Some of those guys could turn into great defensemen, which you need to be a great team (see McDonagh, Keith, Hedman, etc...)
Two points: 1) I don't think we have that much need for Oshie, so I'd rather see if we can find a taker for Tyutin, and keep JJ for a more limited role. 2) Who plays the tough matchups of that d-group? Provo-Savard or Murray-Ellis? Perhaps Murray-Savard could do that and Provo-Ellis could be the offensive oriented pair. Perhaps we need to look at getting a Girardi type back there.
Those projections are intransitive. The scouts who think Provorov >> Hanifin are not the same ones who think Hanifin >> Ekblad. But to answer your question, yes, Provorov is NHL ready, though he might have to be sheltered a bit, just like any young D-man (including Ekblad and Murray).