For a list of planned follow-up issues as we iterating on the parent-child pipeline MVC, please check out our epic for this feature: https://gitlab.com/groups/gitlab-org/-/epics/2750. We welcome your comments and up-votes on the issues that matter most to you.
EDIT: Sorry; misread your first sentence; seems you saw the announcement that there is an alternative to passing variable via artifacts. Please consider opening an issue (https://gitlab.com/gitlab-org/gitlab/-/issues/new) to let us know how you would like jobs to communication.