you and programs like you make up a small amount of measure in AIXI's beliefs

I understand that this is the claim, but my intuition is that, supposing that AIXI has observed a long enough sequence to have as good an idea as I do of how the world is put together, I and programs like me (like "naturalized induction") are the shortest of the survivors, and hence dominate AIXI's predictions. Basically, I'm positing that after a certain point, AIXI will notice that it is embodied and doesn't have a soul, for essentially the same reason that I have noticed those things: they are implications of the simplest explanations consistent with the observations I have made so far.