I created two different map packages (say, mappack1 and mappack2) that included a common layer (polyline feature class in a file geodatabase, say LINE). Then I unpacked mappack1 and edited the common feature class and saved my edits but DID NOT save the .MXD file. I double checked the original feature class and verified the changes/edits. Although, when I opened the mappack2 and checked the original feature class inside of this unpacked map, the changes/edits did not appear in that particular feature class (LINE).
Could it be rooted in this fact that while creating a map package a new geodatabase has been created and after extracting the package it will go through the last generated geodatabase instead of the original one? But I actually double checked the original feature class to make sure about the edits!