"Starting First Hole. The honour is decided by the order of the draw or, if there is no draw, by agreement or by using a random method (such as tossing a coin).
Starting All Other Holes.
The player in the group with the lowest gross score at a hole has the honour at the next teeing area; the player with the second lowest gross score should play next; and so on.
If two or more players have the same score at a hole, they should play in the same order as at the previous teeing area.
The honour is based on gross scores, even in a handicap competition."
This change was effective January 2019.
Australia is possibly unique in playing a high proportion of Stableford and Par competitions. That's probably why it got slipped in without fanfare.
This reverses a change introduced in 2008.
Does it matter? Probably not much. It does keep the matter consistent across all forms of Stroke play. Another Exception biting the dust. (Exceptions make the Rules harder to learn and follow, the fewer the better.)
The important practical thing is that all players get to the next tee promptly to play in correct Order if that is sensible at the time.
By the way “Ready Golf” deals with subsequent play of the hole after tee shots. It is covered later in Rule 6.4b.