A second angle on the counterfactual savings would be Luna telling them not to pursue a potential session with the expected/extrapolated (from which sessions they did ignore Luna on, e.g. just to keep efficiency statistics current) sunk costs at time of getting shut down used to derive the quoted number.
A third angle is that it is not true and that's just some attempt at influencing an HN thread, which is happening quite regularly pro and against AI. We know that the pro-AI has a way bigger budget to burn with this kind of operations tho.