That's what I am talking about as well. The low-level implementation of an agent isn't necessarily a rigid graph, and I'd actually argue its explicitly not this.
This link is also referring to the nodes as agents. So its a system of agents interacting to product an outcome. I'm not saying this system is bad, just that I think it deserves another name rather than calling the whole system an "Agent". It's many agents working in a coordinated fashion.
Not sure about Cursor you mentioned as its agent is not open sourced.