No, you disconnect them from the menu in the People Workspace:
Person > Attach/Detach > Detach
Keep a list of them so that you can search for whether these people were duplicated after the merge and so that you can reconnect them.
Person > Attach/Detach > Detach
Keep a list of them so that you can search for whether these people were duplicated after the merge and so that you can reconnect them.