Closest I've seen is the Teva Mountain Games and the Adidas Sickline competition. That comp crumbled last year due to the title sponsor feeling like it wasn't worth it for the exposure it brought to their brand.
I heard that the higher ups from the X-games came to a Kayak rodeo back in the day (early 2000's) and deemed it to be too niche and too boring for TV. There were a few extreme races around that time like the Gore Race and Green River Narrows race that had more appeal...but that is kind of hard to produce for TV and they never picked up on it.
At the end of the day, Kayak rodeos are hard to sell to the masses. It all looks impressive to those of us who know the sport, but the general public want to see people hauling ass or flying 30 feet through the air or the like and playboating doesn't really provide that. Extreme Freestyle (aka doing tricks off waterfalls) might sell...but its hard to stick that in an arena like they seem to like doing for summer x-games.
Kayaking has been under the gun at the Olympics for a while due to the cost of creating the courses too...we are just too niche for the TV spotlight.
Figure out how to make kayaking easy and cheap to produce or provide a larger mass appeal and you might see it blow up...but it never seems to happen when people give it a chance.
I guess the occasional spot on Redbull TV or the like will have to suffice.