But that's the thing! They ALREADY have all the data necessary within their system to access the long term health effects. They know exactly the sickness rates,
but more importantly the loss of a medical certification (temporarily or permanent suspension) as the employer must be immediately informed as flight duties are longer legal.
This is what make their data set unique. Most employers don't get to peer into their employees medical status to nearly the degree that airlines do. Holding a medical certificated for RPT is binary, you are either medically fit or you are not.
Genuine science could be done with that data set. However, I am reminded of the
words of Sir Humphrey: "No Minister, I beg you," replies Sir Humphrey: "A basic rule of government is never look into anything you don't have to, and never set up an inquiry unless you know in advance what its findings will be."