BWI-SEA works 5/9-5/15, not 5/16 or 5/8 or any other date I tried. The banner appears even if the flight was just booked. I tried multiple routes for 5/12 and it still worked. Maybe it is date and route based but not specific flight based?
Looks like we're gonna need a lot of data points if we wanna milk the free changes like before. That being said, any other BWI flyers out there wanna share?