Speculation here, but I think the opposite. I feel like the general membership would LOVE something like this. Sure, GC talks are considered a type of scripture in a sense to many, but this would be *scripture,* restored and revealed again after thought to be lost for 190 years. And really, it should cover some of the same ground as Nephi, so I don’t know why members would reject it. There might be some textual analysis issues that critics would point out, but that’s the same with the existing BoM. Hasn’t stopped most believers from believing.
But I think something like this could be galvanizing and re-energizing to the Church. If shown to be authentic, of course.