FWIW, kosher Coke is also made with real sugar. Also, just about all foods out of Europe and the MidEast use real sugar. I think you’re correct, that Mexican coke still uses real sugar. I also think there are some Mexican brands that use sugar.
Coca-Cola manufactured in Europe also uses cane sugar. There’s a production quota in the EU on high fructose corn syrup, 300,000 tons per year.
On average, the EU produces over 18 million tons of sugar per year, so obviously, HFCS use is exceedingly rare in the EU.