My account still uses IDCS instead of identity domains

Summary: My account still uses IDCS instead of identity domains.

Content (required): My OCI account(free tier) still uses the old IDCS method for login and I don't see domains in "Identity and Security" I am not sure why is that? I believe the migration of all tenancy to use Identity domain instead of IDCS for login, etc. but not sure why its still not done for my region which is "UK South (London)". I am bit nervous to delete the OICS under federation, in case it resolves this issue. Any help?

Region - UK South (London)

Expected answer: When will the region "UK South (London)" get migrated to use identity domains? Where can I find the list of regions that is already migrated