A while ago, there is/was an article called Gartner Says SDN Has Left the Building – Say Hello to Network Automation. I'm wondering if that is a patato/potato semantics problem: both things say the same thing. Mostly.
One might say that SDN (Software Defined Network) may have been shoehorned into a corner with the era associated technologies such as OpenFlow and the heavy Java tooling used to manage it.
In a similar vein, Network Automation has, in my mind, mostly simple meaning: push out configs programmatically rather than pounding them in with a keyboard. At that level, conceptually you have the identical problem of managing individual configs, but having a faster way of doing things. It does provide config version control management from a push perspective rather than a post gatherer with Rancid.
On the other hand, in the comments following the article, there was a third addition to the typical data/control plane terms: management plane. It is in the management plane where the fun begins. And this isn't in terms of human managers, this is in the auto-collection of network wide data to automatically define operational configurations for devices which push packets. Google's network is such an animal: with metrics backfeeding configuration, they can reach link utilization of over 90% without congestion issues.