There are still few of them in codebase:

• BinlogConnectorIT uses EmbeddedEngine.CompletionResult
• ConnectorOutputTest uses EmbeddedEngine.CompletionResult
• PostgresShutdownIT refers it in the javadoc (and thus it's included in imports}
• ConvertingEngineBuilder uses EmebddedEngine itself
• several classes from debezium-microbenchmark-engine and debezium-microbenchmark-oracle use EmebddedEngine - this is tracked in separate issue DBZ-8444