The denormalization argument is misguided. Denormalization is a performance consideration, and now even happens transparently at the storage layer in some RDBM

The denormalization argument is misguided. Denormalization is a performance consideration, and now even happens transparently at the storage layer in some RDBMs. So restructuring a 'live' database should be done for semantic reasons: because the workflow changes; because the app needs to change.