Let's add another angle to the cancellation criteria: bad and poor reviews.
For anyone doing a great service overall in providing quality stays to guests, there is always going to be a change in circumstances by no fault of their own. Guests are entitled to have subjective opinions and expectations based on what they see in the photos and read in comments. Therefore let it be cancellations or bad reviews, they will affect a great track record.
My points are about:
1) Weighing the way superhost status is achieved and maintained. It is not possible to compare someone with 2 properties to someone with >100 or more. So far that is easy to understand, then why use fixed values that do not take into consideration the size of the business.
2) Number of nights booked (and season): with the current measurement, it does not matter if you cancel a 1-2 night booking in March or a 3 week holiday in August. Both are considered a booking, but the impact economically for the client and host are very different and the emotional impact of losing a key holiday in high season almost impossible to recover last minute vs. a short stay that any hotel can cover are not taken into consideration.
3) Final point, historic data. For property managers that keep updating their portfolio, we always get good and less good properties. however when we get a bad one, that spoils the whole set. In that case, we stop working with bad properties because we can't keep our level of quality...but the damaged has been done, a cancellation or a very bad review now will stain our profile and superhost calculations even after the property is no longer advertised even months later (there is no way to say that a comment belongs to a property no longer advertised due to poor quality).
In summary, after suffering every kind of scenario in our many years experience in the rental business with a portfolio near 100 properties now what I propose to airbnb is to:
1) Create superhost status for different categories based on the size of their business (maybe number of properties published or number of nights booked.)
2) Change the way status is calculated by moving from a fixed number into a more kind measurement like "number of nights booked" That way a negative comment or cancellation in a 2 night booking will not weigh the same as a positive comment in a 2 weeks booking because keeping someone happy for 2 weeks takes 7 times more effort than for 2 nights.
One size does not fit all and if a system is not fair, people will stop believing in it.