No not all are migrated and one reason is that in they do not know what accounts are associated with what customer.
But migration for testaccounts are pretty pointless if klarna doesn’t redirect playground account to kustom since the litium klarna app sends the PK account communication to klarna and not kustom and klarna discards the request after migration.
The solution if one need to test right now is to ask kustom for a new test account that has a PM-prefixed MID. Unless there is a change in the app for PK account they will never works after migration since according to custom klarna has no plans of redirecting klarna playground to kustom playground.
For Litium 7 customers there is not solution to be able to test at the moment (if the test account is migrated to kustom)