Most every airline has the 72 hour reconfirm rule, but most apply it when you break your trip (ie stop over for many days or before your return flight). Most do not expect you to reconfirm your initial departure.
It is a leftover from the golden age of travel, when paper tickets were all there was, reservations went by teletype to foreign airports and offices, when you could swap your ticket for a flight on another airline and change your plans without penalties. In those days they could/would give away your spot if you didn't reconfirm in a timely manner.
Today everything is computerized and penalized, so folks fly on the flight they booked because they don't want to pay the change fees. The 72 hour reconfirm rules are still in most airlines contracts of carriage and appear on eTickets, though they are rarely enforced.
But they do give the airline an out when flight schedules are changed and you complain that you missed your flight ... "well you didn't reconfirm" :p