I disagree with how you've characterized what the incentive is intended to do.
A screening officer who is sick or takes their scheduled vacation is not disqualified from the program.
I'll back up just one step, to your reference to Schiphol.
CATSA is not the employer of the screening contractors. The service is delivered through a third-party contractor.
The process for negotiating compensation is the collective bargaining process. Many of the airports in Canada have concluded agreements already, and there are a few places—Vancouver is one, and Ottawa is another—where the collective bargaining process is under way.
The attendance incentive was put in place because across the country there can be significant instances of absenteeism whereby people don't show up for their shift. The program is administered by the screening contractors. CATSA is making the funds that it underspent in April and May due to the capacity shortage available to incent people to show up for their scheduled shift. If somebody is sick and provides documentation to their employer, my understanding from the employers is that they would continue to be eligible over the 12-week period if they continue to show up for their scheduled shifts.