I would like to know what happens to a Question B that was closed as duplicate of Question A, when Question A gets deleted? Is Question B reopened automatically? Should it be?
As I understand things, there is no connection between duplicates other than the link that is written into the duplicate question, so deletion of the root should not affect the duplicate. I don't know if the link disappears. But surely it's highly unlikely to delete a question that is the source of a duplicate for the reasons below. Do you have a specific example in mind?
When can't I delete my own post?
You can't delete answers that have been accepted.
You can't delete any question that:
- has an upvoted answer, or
- has multiple answers (even if there are no upvotes), or
- has been closed less than 48 hours ago (to allow for possible reopening)