You might want to recover all archived projects, specially if you are planning to run a Jira Cloud Migration and want to make sure the archived projects are migrated.
So if you want to know which projects are archived you can run this SQL query:
SELECT p.pkey FROM propertyentry pe JOIN project p ON pe.entity_id = p.id WHERE pe.property_key = 'jira.archiving.projects' AND p.pkey IN ('ABC','PREM'); -- Replace with your project keys