Hey,
this was shortly described in the blog post here: https://blog.dgraph.io/post/release-v1.1.1/#changes-on-types
I also remember @MichelDiz writing about it here: Linking types to other Types not working - #4 by MichelDiz
I guess this form of typing things will be used soon in the GraphQL API for dgraph https://graphql.dgraph.io/
I am a bit confused why this will be in graphql, but not graphql±, but I guess we’ll know more soon.