They can hang on to 1914 for a while longer by dropping the "generations" explanations. They almost did so in 1995. Why did they bring it back? I can only assume that they want to use it as a way to keep the expectations up, to maintain the idea that time has almost run out. That is what hinders the WTS- they need to keep people in expectation of an event that will happen very soon.
But at some point, enough time will pass that the date becomes worthless or even detrimental. And at that point, expect "new light" and "adjustments in thinking." But they will probably have to find something else to keep the pressure up, otherwise they will lose more and more people.