I don't think that the OP is asking about how long the actual wait times are. She's asking about the Touring Plans calendar which is an indication of how long the wait times will be in general in the parks.
Len Testa is a math guy. His organization does statistical analysis of actual wait times and uses that to predict how "crowded" the park will be. His team's analysis does not intend to say that the park will be at x% capacity but merely that the wait times will fall into a window of expected times during certain hours of the day. If you look at his predictions versus reality, in general, they're very accurate. Most often it falls within 10% (scale of 1-10) of the prediction. His team has even done the analysis showing that even when the park wasn't full in terms of numbers of people in the park, that ride times were high. They found that Disney was arbitrarily lengthening wait times (by lowering capacity) for their own means (they actually had people count the number of riders exiting a ride per hour). Day-to-day, there's always a chance of an anomaly due to unforeseen circumstances (his predictions are based on long-term data analysis and are constantly adjusted). The amount you pay is very small. I do like them (I'm a math guy as well but in a different field) and have used them for picking rooms (for resorts I haven't been to), getting my room request (I've actually learned how they do it and can now do it myself), and determining which order of parks I'll visit. As a Disneyland AP holder, I only use them for WDW. At Disneyland, you can see which park is the busiest and easily walk to the other side (provided you have a park hopper) - so it's not as useful here.