Aa73,
They're still called autothrottles on the A300's that your carrier used to fly.
AFAIK, the autothrust thing started with the A320 series. I never got that deep into the names as after a bunch of airlines and manufacturers you just get used to/accept that there truly is more than one way to skin a cat. I always assumed the name had something to do with the the plane using the the thrust rating detents (TOGA/FLX/MCT/CL/IDLE/REV IDLE/REV) and possibly because of the non moving throttles when the A/THR system is in use. I was always more amused when turboprop and RJ guys, often at the same airline, would get all caught up with thrust lever vs. power lever-more juice, less juice get over it!