I would say this is not intentional but raises some technical questions. Since you can select as many blocks as you want (ie 100, 500, 1000) there can be any amount of objects, so clicking one duplicate button will create as many duplicates as you have link blocks in the selection. So while we do not offer an undo action for this which will revoke object duplication it may lead to unintended results.
We are currently in the process of discussion of this implementation.