I think a bit of the problem here is an over-encompassing and hyperbolic interpretation of the actual facts.
Look at this way, is there an item in the DSM AS dx criteria based on some AS stereotype brand of humor? No. If experts believed everyone with AS has a particular and AS specific sense of humor, then it would be silly to not increase the accuracy of diagnosis by including it as a diagnostic item in the criteria.
What is being referred to is a group trait, not a universal group trait. Liking ice-cream is a trait of the group humans, but is it not a universal trait to that group, many humans do not like ice-cream at all.
It has been observed that many people with AS have a sense of humor that is not typical or common when compared to the general population, and that this style of humor can be correlated to certain traits that are also associated with AS. But anyone who believes that this style of humor is a universal group trait shared by every person with AS, is mistaken.
So if someone tells you that there is some association between AS and a particular sense or style of humor, they are not wrong, but anyone who tells you there is a specific sense of humor common to everyone who has AS is most certainly wrong.