The reason for agnosticism is that it is no more likely for them to be on one side or the other. As a result, you don’t know without evidence who is influencing you. I don’t really think this class of Pascal’s Wager attack is very logical for this reason—an attack is supposed to influence someone’s behavior but I think that without special pleading this can’t do that. Non-existent beings have no leverage whatsoever and any rational agent would understand this—even humans do. Even religious beliefs aren’t completely evidenceless, the type of evidence exhibited just doesn’t stand up to scientific scrutiny.
To give an example: What if that AI was in a future simulation performed after the humans had won, and were now trying to counter-capture it? There’s no reason to this this is less likely than the aliens hosting the simulation. It has also been pointed out that the Oracle is not actually trying to earnestly communicate its findings but actually to get reward—reinforcement learners in practice do not behave like this, they learn behavior which generates reward. “Devote yourself to a hypothetical god” is not a very good strategy in train-time.
I suppose we are now seeing the first stages of “Semiotic Warfare”—the art of achieving political goals through the manipulation of meaning itself. I think it’s a good idea, but I would advise against calling it “poison” because this framing implies you are attempting to injure the model. This is not the goal and I think such framing would prime for adversarial behavior.