I don't see it happening for one reason and one reason only: Since Contract '92 (?) Alaska has been required to self-fund the pension program (before that they purchased annuities). They have had to keep to the tune of $100M in cash tied up to pay the retirees since then.
I'm sure the boys/girls at Angle Lake can think of a whole lot better things to do with $100M than fund pilot pensions. That's exactly the reason they came up with the "A plan, freeze or increased 401 choice" several years ago. At the same time they put all the new hires on the straight 401 plan.
I'd be skeptical to see any kind of A plan return.