The application is to help seed content & activity. As the Op mentions
While not ideal it is maybe better than using sock puppet accounts.
There are already other communities like Discourse using AI in one form or another. This concept could be also used to introduce the AI personas that users can later use if that is an end goal.
Nothing wrong with charging for a service. It helps support development to advance and maintain a product.
Now would I use something like this? Probably not. But ATM that is in general for AI extensions for the forum as it is not within the current budget