This question was migrated to DBA, but my answer got lost in the migration. What Gives?
In this case, your answer was a commentary on the asker's choice of language and not a direct answer to the question, so it was deleted as part of the preparation of the question for migration to DBA.
The banner doesn't seem right, though. In a migration, deleted answers are not migrated with the question, so the banner is incorrect (and of course, a bad user experience).