They aren't claiming 500 net growth. Surely a good amount will be growth. But they got 787s & 350s to retire 1990s 777s, 767s. They also got 321neos/737max to replace 757s, and a crap ton of 50 seat RJs. They are starting the RJ upgauge like we did 10 years ago, just instead using 737s instead of 717s/220s. That will definitely grow their mainline pilot group size.