See the discussion in PR #585(https://github.com/hibernate/hibernate-ogm/pull/585/files#diff-f8ab474572ee0b1af899f95068abd844):

As the order of results returned from MongoDB/Neo4j is not guaranteed to be the same as the order of the requested keys, sub-optimal client-side processing of the result set is needed. This could be avoided if there was a way to obtain the results in the order of requested keys.