What are known efforts to establish DevOps ontology model?
According to Wikipedia, the first reference you linked,


  In computer science and information science, an ontology is a formal naming and definition of the types, properties, and interrelationships of the entities that really or fundamentally exist for a particular domain of discourse. It is thus a practical application of philosophical ontology, with a taxonomy.


The problem with developing an Ontology Model to define the terms of DevOps is that DevOps encompasses multiple domains and these domains can often have overlapping or contradictory terminology.

In fact, sometimes even within a domain there will be conflicting terminology. So it is difficult enough to establish a standard for a single domain, let alone multiple domains.

As such, it is doubtful there will be any attempt (or at least successful ones) to establish formal ontology rules for DevOps any time soon. (And it would have to start with formally defining DevOps first, and so far we have had trouble even making that clear).