Pro wrestling often draws the most 18-49 year-old TV viewers, the target demographic for advertisers, when it's on TV. Pro wrestling is current on four different TV networks (FOX, USA, TNT, TBS) every week and tens of thousands of people see it in person every week. By every metric, including social media, pro wrestling is popular and people enjoy it.
Not saying Flair should have been the celebrity guest picker, but it wasn't a horrible idea.