For that there are already procedures (I advised a company) for genAI implementation and we talk about the risks and gates to shield confidential information.

On the other hand: even if confidential information is shared, any other side has to be aware of that in order to see something…

In other words: how do I stumble across confidential information if I am not aware of it (what do I even search for?)

Nevertheless I would always recommend to take precautions.