Final answer:
It is false that only raw data is replicated across an Indexer cluster; both raw and indexed data are replicated for redundancy and high availability.
Step-by-step explanation:
The statement is False. When a bucket in a searchable index is replicated across an Indexer cluster, not only the raw data but also the indexed data, including the index files and other metadata, are replicated. This ensures that searches can be performed across the cluster providing redundancy and high availability. The replication process within an Indexer cluster is designed to make sure that all data and its indexes are available on multiple indexers for fault tolerance and load balancing purposes.