If that were true the sign would be for ethical sourcing which I agree with. We should punish all who don't out of existence not just cost of business fines.
On plants it's fascinating looking at what they have found. Sending chemical signals to warn others of their species about impending danger when attacked as 1 example.
Obviously there a long way to go before they can answer the question 1 way or the other. But it's not as clear cut as its as ethical as eating a rock like some make out.