Every event has multiple causes, and what causes you point out is not such important as you seem to think. In Newcomb, Omega's decision and your one-or-two-boxing are both ultimately consequences of the state of the world before the scenario has started.

The only difference between Newcomb and the lesion is that in case of 100% effective lesion, there will be no correlation between having read about EDT and smoking. And in a world where there was such a correlation, one should start believing in fate.