It's unfortunate manufacturers don't publish reliability and longevity data on their tires (for obvious reasons). As ChuckSteed said, running any RV tires 9 years isn't the brightest move anyone can make. Yet, I'm confident that there are some, OF ANY MAKE, that will make 9yrs or more. The issue is that percentages of surviving tires, again on ANY make, will go down with time.
Five years seems to be the consensus break-point where it's time to replace RV tires. Because we don't have data, I'll hypothesize that at 5yrs the survivability of good RV tires is somewhere between 98% and 99.8% depending on brand, and how you run them. At those numbers most of us will never have issues over our RVing lifetime. If you buy cheap china-pop's, overload them, and run them at 80mph that number is probably more like 5-10% but there probably are a few that might survive.
With good tires, and care, I fully expect that most can get well over 5yrs BUT the odds of catastrophic failures go up with time and most wisely don't try to squeeze the extra couple/few years out of their tires. If tire manufacturers would give us better statistical information we could all make better decisions, and maybe get a few more years out of tires but that isn't in the tire manufacturers best financial interest.
If you want to run your RV tires to 9yrs, good luck, but please don't drive next to, or in front of me, on the road...