*There biggest problem is they continue to cover union people when they retire under regular insurance, instead of sending them to Medicare when they turn 65, until that union contract expires. *
Not true. Read the health plan summary. If one isn't an active employee, Medicare is primary, and if a retiree person fails to enroll in Medicare, AT&T will disallow payments for medical bills that Medicare would have paid. It should be covered under "post employment benefits" subsection "enrollment in Medicare".
The plans will serve as the Medigap, and pr-scrip-ion plan. So, there is no requirement to enroll in Medicare Part D. And the retiree gets vision and dental for the life of the contract, at the active employee rate.
Some employees are eligible for a Medicare part B reimbursement which would reduce the cost of part B.