Not necessarily. Who is going to pay more for that one extra game? Channel 9? They will still probably take their 3 games as usual.
So the only reason they have for paying more is if the new teams somehow give them access to higher rating games. But adding new teams possibly dilutes the quality by spreading the best players around. Channel 9 have previously stated that only another Brisbane or South-East Queensland club will make any difference to the value of the competition to them. This is because the Brisbane TV audience always wants to see a Brisbane side, which is obviously why the Broncos are always on Friday Night Football. But when the Broncos are playing badly, the ratings in Brisbane drop off. If there was another Brisbane club, there would be a good chance of one of the clubs being in form at any one time. This is not a problem in Sydney, because there are 3 or 4 teams that always rate strongly (parra, saints, canterbury, maybe wests) so there always some of these teams in good form.
So the extra game will probably end up on pay TV. How much more will Fox pay for one extra game per week? Having 2 new teams will cost the NRL about $7m per year in club grants, so Fox will need to pay at least this much extra each year otherwise the new clubs will actually drain money, not add to it. Fox currently pay $42m per year for 5 games per week, which is $8.4m for each weekly game. So continuing this example, if Fox paid an extra $8.4m per year for this extra game it would net the NRL around $1.4m extra per year after the paying the grants to the new clubs. But would Fox pay this same amount for a 6th game? There has to be some diminishing returns here surely.
I am not saying that the NRL won't get more money in the next deal - they will for sure. But the extra money will be due to the existing 16 clubs, and the fact that the NRL got stitched up on the last deal. People like to think it's as simple as saying 1 extra game equals more money, but it's not. It totally depends on whether there's a new Brisbane team (which might increase the free-to-air value) and then how much Pay TV will pay for the extra game.