I can confirm these work for foreigners over 18 on exit from Argentina at EZE - there are no listed specific nationality requirements (though, I have to imagine a chipped ePassport is required). The system is similar to Australia on entry where you have a kiosk to submit your passport, boarding pass, face, and fingerprint. Once approved, you will pass a facial recognition gate (that a guard had to reset for me as I believe it thought my carry-on was a second person). I believe the entry eGates are only for Argentinians.