Linked Issues Status Condition
When you add this condition to a transition, the add-on checks the Status of the issue's linked issues. If the linked issues are all in one of the selected statuses, then the transition will be available to the user. If not, the transition will be hidden.
The list of statuses that is displayed under the Statuses
field has all the statuses across different workflows. This is because the workflow of an issue and that of its linked issues can be different.