While they thrive on the doomsday connection, there's also been a push toward the whole "best life ever" movement and "Christian Life" (CLAM meeting). I could easily see a distancing from the dates of 1914 to a simple but general "look how bad the world is, we give you the 'real life', and a promise of better things to come". They don't need 1914 to keep the end in mind, they have this false hope contrasted with their twisted portrayal of the "wicked world" and I think waiting for their "deliverance" would be enough. They can even still keep the doomsday in mind, but let go of dates. Heck, they've predicted it over and over and successfully moved the goalposts every time to something more vague. They don't need dates to keep the contrast with doom and false hope.
Of course, none of us can do anything but speculate, but losing 1914 would be hard for many older ones. I bet they can be "adjusted" though. That's just how I can see it going down. From what I understand they don't talk about it much anymore, and they've erased their doom and gloom history. Now they can just focus on hating the gays and apostates.