Can we confirm when Sanderson was baptized and partaking? Wouldn't it be awesome if he WAS an overlapper!! The WTBTS would get an automatic 50 year extension! Just think of how many people you know who will be dead in 50 years. Think of how many children will forgo educational goals. Children who could be helping humanity. Instead they will be doing nothing because they have been told myths, the same myths told to their parents.
If the GB really believe their own words, they probably don't mean to say that the system will exist as long as Sanderson is alive. They probably believe that he is one who will be raptured. Still, IF he is confirmed as an overlapper based on his date of baptism and partaking, it provides a convenient excuse as to why the GT has not happened. The longer the WTBTS sits on this, the better. When the timing is right an article will say , " evidently, Jesus meant...."
Then there is the problem of "proving" when someone was anointed. Obviously you are anointed before you even partake. Who can say when that anointing took place? You can't prove that Sanderson was not "anointed" while Franz was living. The date of Sanderson's partaking is a side-point. This provides another convenient direction for the WTBTS to take in the future. Again, timing is of key importance. The JWs who "remember" need to die off. The WTBTS needs to shelve this idea. They don't want the sheep discussing these ideas. This is why they went through the effort of writing an article about marking those who speculate about ideas that are not necessarily unscriptural. The speculation will be "truth" only when the Org says so.