The regionals will have no trouble hiring. There are so many 50 seaters out there that will be retired, a bunch of them, and attrition can take care of staffing. The super senior guys aren't going anywhere, mid level guys will leave if they can. Eagle has this flowthrough but I am sure a lot of the lifers will stay there.
There will be no pilot shortage, well unless you want a job flying empty 50 seat erj/crjs to victorville and other boneyards. The other solution would be to allow captains to fly left or right seat which a lot of captains at all regionals would probably jump all over. In short there will be no pilot shortage anywhere. FOs are the main source of attrition right now not Captains. If Captains can fly as FOs that solves a lot of problems right there.