None of the contracts Accor has with the NRL requires them to play a certain number of Premiership matches at the venue. They only cover things like Origin, Grand Finals, etc and are generally just with Destination NSW versus the venue itself these days.
Bulldogs, Rabbitohs and anyone else who has played at Accor has had a direct deal with the venue and is under no obligation to renew.
This is very different than the AFL's approach to venue contracts. Deals with big venues like Marvel, MCG, SCG, Adelaide Oval, etc are all negotiated by the AFL. The fact the AFL also has equity in Docklands means it's in their best interest to ensure there is a minimum number of games there each week.
In terms of the NRL trying to replicate the AFL's two venue approach in Sydney, beyond the historical attendance culture differences between the two codes, the other major factor that works against the NRL rolling out such an approach is accessibility.
In Sydney, the most accessible venue is Parramatta and then Penrith on a week to week basis. Homebush is fine for major events, but otherwise has zero buses and isn't on a major train line.