I would imagine that they are fielding tons of phone calls from Hollywood, Christian publishers, speaking circuits, etc. They need someone who can tell the bonafide offers from the scam artists. This also protects them from getting used by groups they would not wish to be affiliated with.
The article, of course, makes it look like they are trying to cash in. I do not think so at all.
I know. I'm sure the author of the article was just dying to show that 2 devout christians would dare to hire a money grubbing agent. I'd probably do the same thing if I were in the girls' shoes. Let the agent handle all the publicity.