Demanding evidence for predictions like this is a bit... hm. Arrogant, maybe. A prediction is a commitment. We want people to make predictions. The evidence we get when those predictions come true or not. Would you be willing to make the opposite prediction?
I don’t have any evidence that you will, but since you seem to think that’s ok, here goes!
The complement of the claim is essentially "food manufacturers will never again attempt to modify their recipes to make them more hyperpalatable, now that GLP-1 exists." Does that need evidence? It's the null hypothesis, but it certainly sounds a lot more unrealistic than the opposite.