In my opinion the NRL want Roosters, Souths, Dragons, Dogs, Eels and Wests to be Sydney's only clubs, for these clubs to always be strong enough to be competitive every season, playing each other twice each season, all playing out of the big stadiums and both clubs sharing the day's gate takings and corporates. Anzac Day, Mothers Day, Queens birthday etc etc.
Manly, Penrith & Sharks don't fit in that picture. Even if these three clubs eventually play out of their own rebuilt smaller home stadiums, they will never be able to compete financially.