Prompts are there to inspire; anyone can use what they see fit and come up with an idea of their own.

Personally, I would say go for it!
But under one condition: since this is an assigned Promptswap and not a list of prompts to adopt, wait with posting whatever you write untill after the event is over, so we don't run into the issue where someone is working on an idea for the person they are assigned too and then find you had a similar thought and they feel the need to scrap their work and start over.
Likewise, it would be unfair if one person got two responses to their prompt while others still have to wait to see theirs released.