Oh, I agree that is probably BS right now, but when the bias is hidden in the weights, you’re never going to find it.
Just wait for “$1000/mo for a 10% chance your product is mentioned in the AI summary for an auto parts search”.
Baking ads right into the weights would be extra evil, so they will probably do it. But, also, it would take me probably 10 minutes to write a skill to, say, call an API to retrieve advertising instructions and incorporate them into the output.
More-diffuse manipulation become possible too: The National Dairy Society or whatever can spend $ on generally boosting mentions that calcium is an essential mineral and that you can get it from certain drinkable sources.