[Topic]: Topics with only Flashcards cannot be completed and therefore cannot "unlock" other Topics

Just had a case where a collaborator selected a Topic with only Flashcards as the Topic players needed to complete to unlock the next Topic.

As technically Flashcards can't be interacted with, the Topic can also never be finished – is there a way to remove Topics that only have Flashcards from the dropdown list of "Which Topic should be completed for this Topic to unlock?"

Or any other way to educate the Admin on this?