retiree insurance benefit

My past employer gave to each retiree, that had 20 or more years of service, a $5,000 life insurance policy. We were just notified that the insurance has been cancelled for all retirees. (OHIO) is this legal?

Was there an employment contract in place that guaranteed these retirees this life insurance policy? If not, then this is legal.

Not a written and signed contracted, but published

Do you mean a published policy? Employers' policies have no force of law and do not mean that nothing can be changed. I can only assume the employer decided they could no longer afford to pay the premiums and discontinued the benefit.