A lot of people who frequent Sherdog are more in the know than Rogan. He has his fingers in way too many pies to have the time to dedicate to being 100% up-to-date with daily MMA news. I mean, he's a comedian, a podcast host, an MMA commentator, has his own TV show, etc, etc.
Not saying he's bad at his job, just that's it's unlikely he's aware of every new signing that takes place.
"Not only is the Universe stranger than we think-it is stranger than we can think."