Back to the future. I the 70's and 80's many of the majors flew 65-70 DC9-10's on short haul markets. Republic had CV580's, OZ had FH227's the major airline pilots now realize that flying is flying and it should be done by them.
They also realize that with commuters running around, management will play them against each other. As for retirement, I think you need to have some payoff at the end of your career. Not everyone(in fact only a small percentage) of major airline pilots retire off large widebodies. Many will finish their careers on 757's or MD80's--at pay well below the top scale. In fact, many of the pilots hired will only have 15 years or less to work at the major.
Allowing the commuter people to flow up into mainline--in reality making it all mainline eventually, is a bonus. You don't have to spend your days off sending out resumes and worrying that you'll be stuck at a commuter the rest of your career.
I hope AA sees the benefit of "Onelist".