It is silly, of course, to think of s's probably being B as itself a condition of s that we could receive information about, as something that could have a conditional probability of 1 and that therefore qualify as the informational content of a signal.But maybe it would not be silly if s were a quantum mechanical system. We could receive the information that Schrödinger's cat is probably dead, and that could indeed be something that could have a conditional probability of 1?
("The King is probably dead: long live the King!" Where was that from? I've feeling it was in Blackadder, or did I imagine it?)