The terms “yank” and “seppo” were more common in older generations of Australians. If you could go back to the 1940s, I think you’d hear both terms a lot (in certain informal contexts)
One still occasionally hears “yanks”, but it is quite rare. “Seppos”, one more often hears joking about calling Americans that than anyone actually doing so-and the rare occasions the term is used (as opposed to merely mentioned), are (in my personal experience) self-conscious exercises in derogatory jocularity-related jocular coinages are “Sepponians” and “Seppostanis”
Of course, it is a big country, and terms which have fallen out of general use may be retained or revived in some pockets-I can only describe my own personal experiences
One still occasionally hears “yanks”, but it is quite rare. “Seppos”, one more often hears joking about calling Americans that than anyone actually doing so-and the rare occasions the term is used (as opposed to merely mentioned), are (in my personal experience) self-conscious exercises in derogatory jocularity-related jocular coinages are “Sepponians” and “Seppostanis”
Of course, it is a big country, and terms which have fallen out of general use may be retained or revived in some pockets-I can only describe my own personal experiences