My guess, Retirement age raised to 59, the goal is to get as many senior people out before they hit 30 years of service and 55 and next 30 and 59. This will push any retirement payment's till you are 65 saving UPS hundreds of millions
The legal language in the retirement contract is very tightly written.
The idea that future gens of UPS Management Committee could not easily change it to do things like you are talking about.
When every buyout was offered, I heard the Accounting folks complaining about how the "pension" language was airtight.
One thing going our way ... hopefully.
The cost to UPS is pretty much the same ... look at the monthly payout before retirement age 65 back to age 55.