What functionality is missing? What is unsatisfying with the current situation?

  The large pile of prompts World Anvil provides is a good resource, but very frequently it makes me think "I already did something that would fit this perfectly."  

How does this feature request address the current situation?

  This would let people apply new prompts to older articles. Not for formal contests but for the informal prompts only.  

What are other uses for this feature request?

  For people who check the prompts to find other people's articles to read, this will lead to them having more articles to read.