*spoiler alert*

It seems clear to me that the Tallyman itself is the AI in this allegory, a man-awoken sentience that's mechanical and mathematical in its behavior.

It's also bound by rules it can't violate. It won't say more than it needs, it can't collect without squaring the account first, etc.

But I agree with you about the moral message, I can't find it. In the story, the rules it abides by seem to be its own, and there's nothing saying those rules should not exist.