That isn't necessarily true. If the IRS laws change, the contract would have to be modified or amended to be in accordance with any new changes in IRS or Erisa laws.

Example a Lump Sum option on our "A" plan.

We currently don't have one but many of us wanted it. There is currently a debate within Congress to place a ban on Lump Sum distributions (Pension Relief Act). If congress does in fact pass a ban, Lump sum options would become null and void. What I am saying is, we could have spent a lot of negotiation Captial to achieve a lump sum option and with the stroke of a Pen, It is gone , courtesy of congress. And Fedex MGT would say "It isn't our fault , we are just obeying the Laws" (Just like they did in 1993-keep reading below)

The same thing goes for our B plan. Many people pretend to know what will happen to it if AGE 60 passes (or is overturned to be more accurate).
The truth is, nobody really knows how the IRS will rule. We all have our opinions but nobody truly knows what will happen. It is that unkown, that has many folks worried about Age 60 changes.

If AGE 60 does change, Yes we will still have a B plan, and yes the company will still make contibutions. The worry is "Will the contibutions be taxed before they are deposited?" Will it now count as income for w-2 purposes? That small potential, could drastically affect a B funds net worth over a 20 year career.

Many over 60 advocates say this won't (can't) happen. Maybe they forget the Omnibus act of 93. which capped the max income for retirment calculations. (many Retiring Fedex Pilots at that time lost 20-40k per year in Pension payouts.)
The bottom line is No one really knows what will happen.