I came here in the hope of finding a solution but I'm disappointed.
I agree with others.
It's 2020, 5 years passed after reporting this bug still, Autodesk didn't repair it.
There should be an easy way to unlink components after pasting.
Any new user will think his copy-pasted components are individual.
I'm facing this issue, I have an assembly which has 12 big gears and 10 small gears all 12 big gears are copied and pasted from 1 big gear. Using Move command by selecting create copy check box ON.
Tones of other components are there which are sketched and developed on the faces of these gears. There are more than 250 features in timeline history including joints and motion links.
After showing the design to my client (friend), he demanded to add a handle to the outermost big gear. But today when I started editing outer big gear (second copy of the original) all big gears started changing.
I'm unable to delete that gear because, that gears lie in the timeline at a very early stage, around feature number 4 or 6. I tried to delete it but, the whole assembly is disturbing because of the absence of that gear. All 250+ features are disturbed in the timeline.
Now how should I proceed in this condition? What's the solution for me? Recreating the whole assembly is not possible, It requires 1 month. The client wants this assembly completed by today, he is saying, why you need extra time to just add a handle.