It does, but it's not at all related to what they're talking about here, at least as far as the text describes. The issue is that large aircraft require an air

It does, but it's not at all related to what they're talking about here, at least as far as the text describes. The issue is that large aircraft require an aircraft model specific training program called a type rating which is rather involved and expensive. Both Boeing and Airbus have common type ratings across multiple aircraft models and sub-models to save on training costs for airlines. To do this, they need to maintain a high degree of controls and systems commonality between the types and in this case, they fudged these limitations by adding a system which was a significant departure from the older 737 type and type rating training programs without requiring additional training on the MAX sub-model.