I'm sitting here with a United Purser of so much seniority, he started with Pan Am and has been with United since Pan Am went to the pearly gates of FL410.
His comment is, the lowest value route will always cancel the first, then the nearest distance to base, then the easiest to reassign passengers.
Take from that what you will.
EK77WNCL, in response to your comment about an ETOPS 737, his sardonic comment was "Sure honey, you want us to whip out a 737 and crew from our ass, have it all ship shape and ready to fly across to Europe where it and the crew have never been before and where there'll be no one to fly it back and where there's 20 seats less just by clickin' our red shoes and wishing it to happen...uh huh.....?"