the model is not sustainable in its current form for the operators. However it is required by the majors and sustaining it will be cheaper than losing it. Just my guess, but I see more exclusivity to the regional airlines, since majors will be pumping money into them, and wont want to pump money into someone that will be also doing business with their competitor. For this reason, I see some airlines just cutting out the middle man and using the wholy owned mores. Staffing will be easier as well if they flow up wholy owned airlines.

There will never be a shortage at the majors level ever, never ever ever ever ever. The drunks, 3x failed checkride, felon, weirdos will never ever ever get hired at a major airline, unless they flow up of course. However the regionals I assume will have a really hard time over the next 5 years, but that is easily fixed, say for example AA took 50% or even 75% of all new hires from Eagle, then Eagle would never have a recruiting problem, I think this type model will be seen everywhere.