The direction is not a meaningful attribute for core links. It is simply a handful way to make links easily readable and therefore they are bringing some arbitrarity when a new link type is created. However, the direction is a critical concept in Links hierarchy since it only rewarded linked issues that contribute to their ancestors in the hierarchy and finally the root issue.
To avoid organizations from reconfiguring core lin types directions in Jira, a new feature is supported from the 5.3.0 version: Reversed links. It allows switching link directions with a single click. This change has an internal impact only. They are reversed in Links Hierarchy only and remain unchanged for the rest of Jira and other-third party apps.
For example, Atlassian Jira Software supports splitting issues from the backlog. However, the link direction is not expected by Links Hierarchy and, therefore, the split issues do not contribute to their ancestors' progress:
This can be resolved now by reverting the links to the expected configuration:
Server/DC
Cloud
This new feature allows you to decide in which direction the links contribute to the progress roll-up.
Let's see an example:
from a board, you can split an issue...
