The self awareness grows
I will have to side with Gok on this one, there were a lot of parallel imports back then so they wouldn't have been distributed through MB, I am sure the ex MB employee in correct for their own distribution history and as I remember the boom definitely came in 1985 in the toy stores, but the market was getting flooded with all things 80's toys around that time so for independent retailers to have TF's in 1984 is not a huge leap of faith.
I specifically remember that there were signs in my local toy shop that mentioned TF's being toy of the year of 1984 or 1985, I am leaning to 1985, with the 1984 line coming out in September in the US it would be unrealistic for it to be given the award in Australia.
I think until definitively proven otherwise we should go with soft (unintentional) release in 1984 at small shops and mass release in 1985.