When you publish a call flow, Architect “snapshots” the prompt and stores it with the published flow. 

Deleting a prompt from the User Prompts tab that is used in a published or active flow has no effect on that call flow. When you delete a prompt, you also delete the prompt’s resources. You cannot delete system prompts.

1. From the Architect home page, click or hover over the Prompts menu and select User.
2. To delete one or more prompts, do one of the following:
   • Select the check box next to the prompt you want to delete and click the Delete button.
   • Select the check boxes next to multiple prompts you want to delete and click the Delete button.
3. In the Delete Prompt dialog box, click OK.