> This shallow architecture exploits the computational capacity of cortical microcircuits and thalamo-cortical loops that are not included in typical hierarchical deep learning and predictive coding networks.

As I understand it the thalamus is basically a giant switchboard though. I see no reason to believe that it never connects the output of one cortical area to the input of another, thus doubling the effective depth of the neural network. (I haven’t read this paper though, as it was behind a paywall.)