I'm not sure if I'm missing something (perhaps the joke, as it were) but the Calvin & Hobbes strip seems to be entirely about having a sense of humour, rather than a theory of comedy.
It's an interesting thought and a question "why did sense of humor develop through evolution?". I don't think this comic applies to the author's post though. Which is more about how to produce comedy, and seemingly quite one dimensionally?
Also I don't think the comics final answer is satisfactory, because you could definitely respond to absurdity, by calling out why something is absurd, you don't have to laugh at it.
So why do we have a sense of humor in the first place?
The C&H explanation has two parts, what triggers the humor response (perception of things that don't make sense) and why we have the humor response (evolutionary fitness). A theory of the humor mechanism should be congruent to a theory of comedy.
The physiological manifestation of the humor response is also explained by evolutionary fitness when you consider it as countering the physiological reaction to the perception of stressful ambiguity.