The way things are headed 100 years from now we are going to be communicating by grunting noises and back to drawing images on cave walls. Bronco Bama will be some horror story told via oral tradition.
You are unreasonably pessimistic. I think 100 years from how at least 0.1% of survivors will be able to read and write as many as several hundred words.
But the language may change, as clay tablets are not very convenient for cursive. Cuneiform may become popular again.