I wouldn't call what he's doing "chasing the upgrade". He's not picking one specific place that has super short upgrade times and going for just that reason. He will likely never upgrade at express jet. If he's making a move to improve his career overall then I would say go for it.
Bottom line there is so much movement at other regionals there's no reason to not be apart of it. Express jet and awac are such great companies but how could anyone honestly recommend someone go there or stay there? If you're less than 2-3 years in get out for sure and if you're more you should still be strongly considering it.