I am sure the other planets will be replaced (just like Qo'noS in "Sins of the father"). Deneb IV however was a painting, and as you can see, keeping it was the right choice because all the tiny details can finally be fully seen.
The first planet seen after Deneb IV is Ligon II in "Code of honor". I'm sure it will be redone and will look spectacular.
You'll get no argument from me. I think the painting of Deneb IV looks great in HD!