I think it's important to distinguish the meta expert from someone who is just better at teaching X than doing X.
For example, there are world-class sports coaches who aren't world-class at the sport they coach.
That's not who I have in mind with the term Meta Expert.
Perhaps even my real-estate example isn't a great one. The "problogger" is perhaps the best example because technically they are blogging professionally but they just blog about blogging. Hence the "meta".