The letter never mentioned the word immigrant or implied immigration.
Border vernacular has a term but its pronunciation is an uneducated hybrid, TexMex, compounded by the difficulty for the English listener because the sound of the letter i in Spanish approaches an e in English. To a gringo, EEN-ME-GRAHDO sounds like M-ME-GRAHDO sounds like EEM-ME-GRAHDO.
Even in the US, a majority of the population does not know the difference between emigration and immigration. Expecting an even less educated population to know the difference between emigrado , used in the letter, and inmigrado, which the US press conveniently used as the translation, is unrealistic.
The problem appears to have arisen because a scholarly translator was employed instead of a street kid.
Nevermind my previous post, I have just read yours, Amerigomag, and some others'. Thanks for updating me. I suspected this all along!