"excluding products where those substances occur naturally."
That seems like a dumb exception. It's not like naturally occurring caffeine is somehow better for you. If it's above that limit, then the law should apply to that as well.
Coffee has its beans dried and roasted, then ground and seeped in water. If you're going to call that artificial, then you are claiming that literally any cooked food is also artificial.
Coffee beans are dried. Then beans then ungo a Maillard reaction, caramelisation, pyrolysis and decarboxilation to form new organic componds
then ground and seeped in water
Then ground to maximize the surface area. The prouder is then extracted using unpure H2O as solvent. A higher temperature is needed to raise the solubility of the compounds.
Yeah that's basically the point I try to make. You can't even say it's not synthetic since you're synthezise new compounds in the first step. There really is no real difference artificial and natural.
Let's take Vanillin (vanilla flavoring) for example: you could extract it from Vanilla, but it's pretty expensive this way. You could also just synthesize it from wood pulp and get the exact same compound. It's not even just similar, no, it's the exact same.
If something is natural or "artifical" doesn't say anything about how harmful it is.
I'm gonna go with the step you didn't list which is soaking them in dichloromethane or ethyl acetate for several hours, or submersing them in high pressure, supercritical carbon dioxide, to extract the pure caffeine. Then adding that pure caffeine into a mixture of artificial sugars, preservatives, and food dyes.
But sure, that's totally the same as something that's essentially a type of tea.
I would argue that naturally occurring caffeine is much worse than synthetic caffeine because it also contains rest of plant's toxins and other not so good stuff.
On the other hand not that anyone uses sunthetic caffeine in their drinks. It is expensive as hell.