So learnable, in this context, rhymes with reverse-engineerable?
Identifiability means that out of all possible models, you can learn the correct one given enough samples.causal identifiability has some other connotations
See here https://causalai.net/r80.pdf as a good start (a nose in a causal graph is Markov given its parents, and a k-step Markov chain is a k-layer causal dag)