Auto topic creation on the broker has caused pain in the past; And today it still causes unusual error handling requirements on the client side, added complexity in the broker, mixed responsibility of the TopicMetadataRequest, and limits configuration of the option to be cluster wide. In the future having it broker side will also make features such as authorization very difficult.
There have been discussions in the past of implementing this feature client side. example
This Jira is to track that discussion and implementation once the necessary protocol support exists: