IMO not if you mist enough, to each their own though. People were keeping veileds close to 7+ years before petr came out with his naturalistic hydration. Don't see any problem with it, but time will tell if it really makes much of a difference. It tends to be hyped up by the newer to the hobby people because it's all they know and their chams are doing well with it, but chams were doing well before it came out too. I'd say go with what works for you, in most cases, hydration is hydration and will achieve the same goal.
Also petr says humidity doesn't matter and you still need the fog as high humidity and fog aren't the same.