Thinking about the NRL doing away with Saturday night finals in Weeks 2 and 3, I think I may have a thoery as to why the broadcasters, especially Channel 9, haven't objected to it.
In relation to free to air TV, Saturday nights are considered their "low ratings" night of the TV week. AS such having premium content, like an NRL Finals mnatch, whilst It might rate, is not a time slot advertisers will usually spend a lot of money on. By having the games at 4.00 pm (AEST) on a Sunday instead, it gives them a big lead in audience for the 6pm new.
Fox won't care as much as content is what they care about on the whole.
The Grand FInal though, Nine will resit it being afternoon time. Sunday night is free to air TV "big ratings" night of the TV week, and jhaving the NRL Grand Final will rate and enable them to charge a premium for advertising. That's whyt I don't think the NRL will oush to move it away from a Sunday night, especially as it being held in NSW, the Sunday it's held on is on a long weekend.