That's what I say. Surely they remove the warhead bus before they fire off one of these.
I have no experience with SLBMs, but it seems that it would be an amazing and reckless waste to have a nuclear warhead just crash into the ocean in the target range area. At worst, somebody could PROJECT JENNIFER us. I would expect that the missile would be fitted with additional instrumentation or ballast that exactly matches the payload weight and balance.