If you merge and replace existing geomerty and that geomerty was Excluded from a camera or part of a Corona distance shader it will lose its link or will show to that camera, Please allow us to reload a geomerty with the same name and UPDATE all those shaders or cameras without losing its links.
One big example is the camera exclude with AXYZ anima, every time you update the anima file all cameras will render all those objects that where excluded by the render camera list feature.