I have this fear because there's a history of that with novel query languages and DB platforms tossing in network/hierarchical/"document"/object-oriented features, and creating a dog's breakfast which loses the compositional/expressive power of the relational algebra. Think MongoDB or Redis. Conceptually a big mess.
RDF itself has a history of this as well. Appeals to novelty.
Or even Google's F1, which smashes hierarchical tree-structured protobufs into a SQL DB, and so has really weird behaviour on joins and projections.
Well, whatever, you know my opinions on this stuff, I think :-)
At this point I'd settle (or ask for) for a network available tuplestore which just receives relational-algebraic operators from a client, and optimizes/executes, and returns pure tuples, and the client-side could formulate whatever query language (or API) it wanted on top of that. I started playing with building something like that between the two jobs, but never got far.