The NRL will be conscious about what has happened to other sports when they've disappeared too far behind the paywall, so I'd imagine a 9th game will end up equating to a 4th FTA game. There's multiple ways of negotiating it too.
Also, if 9/Stan gets everything, then you could end up seeing some 5 FTA game rounds (like Easter, ANZAC Day) as there is less reason to restrict them as it's not against a competitor.
Finally, I'd be placing a big question mark over Channel 10 for the future. There's multiple take over and restructuring offers for Paramount. The latest is from Apollo Global which is actually a big mindboggling if you look closely at the details. Either way, they're in a bit of a holding pattern until we know what happens with CBS and if it's spun off or kept in the Paramount group.