usually when a product or component is reaching end-of-life, there already exists a successor product.
It would be helpful to learn about this product. Especially, when the successor is not obvious.

E.g. Red Hat Enterprise Linux 8.4 is EOL. https://access.redhat.com/support/policy/updates/errata

"In Red Hat Enterprise Linux 8, EUS is available for: 8.4 (ended May 31, 2023)"

The obvious successor was RHEL 8.5, but you also might want to update to the latest 8.X.

Thus, the field for the EOL-notification could look like this successor: "RHEL 8.5 or later"

In other cases, a release might be the last of its kind.

E.g. open source ISC-DHCP server has reached EOL by end of 2021. https://www.isc.org/blogs/isc-dhcp-eol/

The product is discontinued, but the ISC is replacing it with a new implementation: https://www.isc.org/kea/

Thus, the field for the EOL-notification could look like this successor: "Kea DHCP, https://kea.isc.org/"

In other cases, one discontinued component may have several competing successors.