When we use linked nodes and if Blender can not find this linked file, then this nodes automatically broken. This is normal thing, but Blender must shows a window and says “This files can not find, select file location” etc. like 3dsmax. In this way, we are never loss any data without knowing.
Otherwise, we loss data and we can not know loss (if we didn’t look console), and if we save this file, our node setup will broke.