I believe you're both correct, just in different years. A few years ago, maybe 3-4-ish, there definitely was a Mexico booth in Italy by the wine stomp photo op wagon. [Edit: no there wasn't, see my follow-up post below and revel in my shame.]
Shamefully, I will admit I remember this because the cultural ambassador working the front line area of that very booth at the time was stunningly beautiful. Gorgeous. She was almost as beautiful as my wife, from whom my imaginings did not stray for even one fleeting moment as I took a bit too long to chat with this effortlessly engaging and doe-eyed beguiling vision from Mexico. The setting was unquestionably San Marco, as I can hardly forget where I was when I once again laid eyes on my wife and forgot entirely about the arresting visage of this lineal descendant of the Mayans' own Helen herself, Ix Naah Ek’.
Probably my favorite booth that year.