As the 752s start to age out of the fleet (it feels like a minor miracle UA is still flying them especially with how long ago the pmUA 752s were purged from the fleet -- though I know there were specific reasons for those retirements) I think that will be less of a factor and we'll see ships like the 7M9 and 321 deployed on those long-but-not-too-long and thin-but-not-too-thin routes. That is, of course, on UA actually getting aircraft delivered.