Yes, when you create a new index, you can choose the index implementation. The previous one was called 'upsidedown', and this one used key/value stores for the actual storage. So, you would also specify BoltDB/RocksDB/LevelDB/Moss/etc. The new index implementation is called 'scorch' and it writes directly to disk instead of going through a key/value store.
Not yet looking into scorch. So scorch would replace other storage engine like rocksdb and leveldb?