In my view, semantic web technologies should have been used to make databases interoperable, not to turn the hypertext web into an incredibly incomplete distributed database without any data quality process.
But what can you do? At this point, keeping federated alternatives, protocol-first designs, and multiple interworking implementations is more important than purity; it might well be the last successful initiative of its kind.
No, I wasn't even aware that they use anything RDF related.
And the current trend is really to connect the AI layer of Foundry with the ontology layer.
Note: after rereading your comment, I must admit that Foundry enforces data co-locality and model co-locality (==a unified centrally managed ontology). Which are NOT what the semantic web wanted.