I don’t think there is a direct or easy way to do this using Graph API and infact I don’t think there is an API to get the list of site collection owned by a user. one way to do this You might have to figure out which groups that terminated user belongs to, replace the terminated user with the manager for sites using groups
Yes, I think you can do this using REST API (via _api/web/roleassignments to remove the terminated user and add the manager as a site collection admin or owner.
We have SharePointOnline set up as a connected app (using the SPO connector)…
Wondering if this can also be done maybe using a transform/rule? When the LCS is set to terminated, the transform or rule can be triggered?