I think it may be helpful to clearly distinguish between epistemic and instrumental rationality. The idea proposed in this post is actively detrimental to the pursuit of epistemic rationality; I should have acknowledged that more clearly up front.

But if one is more concerned with instrumental rationality ("winning"), then perhaps there is more value here. If you've designated a particular goal state as a winning one and then, after playing for a while, unconsciously decided to change which goal state counts as a win, then from the perspective of the you that began the game, you've lost.

I do agree that my last example was massively under-justified, especially considering the breadth of the claim.