I believe in Australia this is a legitimate concern for the society, just from what I have heard from other elders. Sure there are plenty of elders that are in their 30's and 40's but I think around 50% would be over 60. There are two congregations that I know of where they are all late 60s and 70s except a couple of elders in their 40s. Even the average age of some whole congregations is very high. At least half of my cong will be buried in the next 10 to 15 years.
The younger JWs are a different breed from the old faithfull. They are nothing like the zealous devoted old timers. I reckon the younger ones would put far less in the contribution boxes then they would have decades ago. Like Pyrimad Scheme said, they are scraping the bottom of the barrel, they are gonna have to lower standards otherwise they won't have any brothers taking the lead. The only young ones I see reaching out are doing it to make themselves more attractive to the spiritual opposite sex. There are exceptions of course, but the society does not have anywhere near the numbers they need reaching out to replace the others soon gone.