Sorry but this is incorrect. I lived in Peru for 4 years and speak to my Peruvian wife in Spanish everyday, they use ahorita the exact same way they do in Mexico, Peru even uses more diminutive than Mexico, and I know it's the same in Bolivia, Chile and Colombia that I have visited. Looks like the author of this article doesn't know a lot about Latin America. I also know Puerto Rico is big on diminutive, so I'd say it's pretty much every single country in Latin America that speaks Spanish, they all use ahorita and even ahoritita this way.