Originally Posted by vernonc

AC has too many generic reasons for cause of delay. See example below from my first roundtrip flight of this year.
This flight is delayed due to an operational issue from an earlier flight which is causing the aircraft that is scheduled to operate your flight to arrive late. An example of an operational issue could include scheduling conflicts, operational decisions or a connection delay.
Situations surrounding flight disruptions can be complex and have multiple causes. We are required to inform you of the reason for a flight disruption. Please be aware that the reasons provided for a flight disruption may change as the situation evolves, new issues arise, or new information is received.
So operational issue does not really explain anything.
This flight later had the delay changed to weather related due to late incoming flight.

Then the flight was eventually cancelled. See below for cancellation reason - which covers all weather related without being specific.
We're very sorry, this flight is cancelled because of weather conditions at the departure airport, destination airport, or en route.
Weather conditions can affect flight operations when thunderstorms, snow, fog, low clouds, air quality, wildfires or flooding make it unsafe to take off, follow the planned route, or to land, for an undefined period of time.

Originally Posted by vernonc

See below for another flight. Not eligible for compensation due to additional time needed to address pilot scheduling issues. Why is this not eligible for compensation?Official Disruption Reason(s):This flight is delayed due to additional time needed to address pilot scheduling issues.

Originally Posted by D404

Sure this one is unambiguously due APPR compensation, though? Swear I recall this cause, specifically, being ruled on.