Clark talking about multiple possible (driver/entry) "changes". I fail to see any clear candidates tbh.

Sure Řstberg with C3 is a possibility, but he is already entered.
A distant shot might be Rovanpera in 4th Yaris. Here it would somehow make sense that they didn't want to announce it before Skoda secured title.
Even more distant shot might be O. Solberg with WRC (Fiesta), but that would also have been announced earlier.

Some people would think about Hyundai, but that doesn't look likely to me at all as it's one of Mikkelsen's best rallies and he has shown good recent form and consistency. Similarly Sordo is the definition of consistency this year, while Breen has bad recent record and bad record in Australia in general. Loeb I think has not driven Australia at this location a single time and was very vocal about not doing more than 6 rallies.