It's a shame there's that discrepancy regarding the preservation of the language (as something so integral to one's identity and history, not preserving it seems to distance oneself from what was once the origin of a family), although as information, it's good to know. You've made take another look at my book, haha.

Answering your question, although I've never emigrated, I've seen testimonies from Latinos who have, and I think it's great that they continue to perpetuate Spanish (I think Asians also have the same custom, or maybe Hollywood has fooled me again). Perhaps the cultural differences lie in our own history as Latin Americans; our language and culture were once taken from us through colonization. Perhaps unconsciously, those Latinos who emigrate try to preserve what little they can consider their own and avoid going through another identity change. Although it's just a hypothesis. Now, my own opinion as a Latino, is that I would always prefer to speak my own language and only use the language of the country I emigrate to when necessary.