I don't think it's a question of new and historic zones, as a new zone can also be a historic zone. It's just a question of whether you want landscape to be re-used.

Frankly, I just want good content, a gripping storyline. While I'm eager to visit new regions like Rhun, Nurnen and Harad, I also don't mind if they re-use existing landscapes, to tell a new story in it. To my thinking, if the landscape is already in place, they can focus more on brining it alive by placing new assets in it. War-camps, battles etc. Remember we had three versions of Isengard, and seeing it in a different state each time was actually quite nice. It will be the same with the Scouring of the Shire. I definitelly don't think every zone lends itself to this kind of treatment. But if there is a rich history surrounding that zone--especially focussing around a particular timeframe--I don't see why not