They sold a modest portion of their holdings for around A$15M in on-market sales. They still hold a ton (just under 5% of the total equity). Their sales equivalent to maybe 1 - 1.5% of the company's total capital over a 5 month period. Not overly significant nor newsworthy, except they've gone under a 5% holding so they've 'ceased to be a substantial holder' and that has to be reported.
Clearly they haven't given up on DTR considering they're still very much a T20. Maybe they simply got tired of leasing their private jet and decided to purchase one...