A disruptive hypothesis is an intentionally unreasonable statement that gets your thinking flowing in a different direction. It's kind of like the evolutionary biology theory of "punctuated equilibrium," which states that evolution proceeds slowly and every once in a while is interrupted by sudden change. Disruptive hypotheses are designed to upset your comfortable business equilibrium and bring about an accelerated change in your own thinking.
The ability to ask, "What if?" is an essential part of every executive's skill set.