End result: Captive workforce!
Disagree Krusty. End result: No Rex.
In an environment where the consequences for errors can be brutal, a seriously disgruntled workforce (pilots without options) is insane. An MPL, as simply envisioned with Rex above, has Buckley's chance, unless the crew is seriously dumbed down. The industry can't go much further down as it stands.
I'm sure there will be career MPL's, but with most, it will be a step towards further qualifications. From Rex's current position determined not to pay a decent wage, it will probably mean the difference between pilots staying for one year or staying for three.