How do I migrate a race character to its parent SSF league?

During and after the race I see characters on the ladder showing as "Retired".

How are they doing that? Does it just mean they deleted?

Or is there a way to migrate that I can't find? When I click the League Migrations chevrons nothing happens. "There are no available leagues to migrate progress from." My character seems stuck in the child league "Act 3 Boss Kill Race 2 League".