I have no doubt someone out there somewhere will follow up on exactly what you've suggested.
Elaborate? Legitimately curious
That said, turning a tool into a profitable business is another story entirely; if one person can turn an idea into working software with the help of AI, dozens more can too. So I'm also curious, not just from idea to software, but from software to business and millions of income.
For starters not many people need story boarding.
When someone is actually doing a project that is big enough to need story boarding, they are going to have some infrastructure and making a wrapper around prompting image generation is not going to be far fetched.
The narrow window of productions that are doing story boarding but think they need a tool to wrap image generation and have no one to script some tools themselves is pretty small.