Another BenefitsLink discussion raises the same worry.
https://benefitslink.com/boards/index.php?/topic/69012-lifetime-income-illustrations/
ERISA imposes the new requirement on a plan’s administrator. For a typical single-employer retirement plan, the employer is the plan’s administrator. If an employer did not ask its own employee-benefits lawyer, an employer might be unaware of the new requirement. When an employer/administrator learns of the new requirement (and that no recordkeeper offers a service to meet it), the administrator likely would seek a service from its third-party administrator.