You are 100% correct. However, if you say “it’s possible to have agents that behave as if they had precommited”, then you are not talking about what’s the best decision to make in this situation, but what’s the best decision theory to have in this situation, and that is, again, meta-Newcomb, because the decision which decision theory you’re going to follow is a decision you have to make before Omega makes its prediction. Switching to this decision theory after Omega makes its prediction doesn’t work, obviously, so this is not a solution for Newcomb.
You are 100% correct. However, if you say “it’s possible to have agents that behave as if they had precommited”, then you are not talking about what’s the best decision to make in this situation, but what’s the best decision theory to have in this situation, and that is, again, meta-Newcomb, because the decision which decision theory you’re going to follow is a decision you have to make before Omega makes its prediction. Switching to this decision theory after Omega makes its prediction doesn’t work, obviously, so this is not a solution for Newcomb.