I remember watching a video (something like https://www.youtube.com/watch?v=NY66qpMFOYo, but probably not that exact one) where they did the analysis and determined that Mexican cane-sugar coke contains the exact same proportion of sugars as HFCS coke - and it's because of the chemistry of how the sugars break apart in the presence of acid in the liquid.

So in theory an extremely fresh mexican coke might be different, but in practice you're getting the same thing.