|Orange leaves on Japanese blueberry as they are dying and falling off.|
It is hard to say "after the fact" on something like this. All you can really say is that the leaves have died and will fall off. Now the question is whether "the death" went further than this or not. So you would normally take hold of the branches with dying leaves and bend them. If they are supple and the leaves drop then it was a recent "trauma" to the plant and you cannot be sure yet if the death is going further or not until you see new growth. You can be pre-emptive and cut these branches back and force new growth or wait, your call. The fact you are seeing new growth is very positive.
You realize that Japanese blueberry is not the best choice for a carefree landscape in Las Vegas. It is best planted in a part of the yard protected from late afternoon sun and it will definitely not do well in a rock landscape.