Well I guess without abstract reasoning ability (and thus no conceptual context in the human sense) "understanding" in the way the word is typically used is pre

Well I guess without abstract reasoning ability (and thus no conceptual context in the human sense) "understanding" in the way the word is typically used is presumably impossible. But I don't see any reason you couldn't train a model to incorporate the underlying assumption that the flow of time is unidirectional. I expect you would just need inputs (ie training data) reflecting that fact coupled with an appropriate loss function. (Aren't networks that predict future physical states, such as motion, more or less doing this?)