I don't think anybody is in trouble yet. I also don't think JetBlue or Southwest have anything to fear.
/US hasn't happened yet. Oh yea, it's announced, maybe financed, still needs government approval, then the real work begins. Which operating certificate to use? Employee groups and seniority issues. Headquarters combining. Layoffs. The list could go on.
/US is successful, I still don't see JetBlue or Southwest having any worries. More competition is not always bad.
I don't understand everything I don't know about this.