Delegates from the so-called Tier One unions discussed plans for the next World Cup at Monday's chairman and chief executive's meeting in Auckland.
The smaller unions have built a strong case for World Cup organisers to implement a level playing field with regards to fixtures.
Samoa, for example, had to play four times in 16 days in a pool featuring Wales and South Africa, who both had more generous fixture lists.
A World Cup statement said: "The tier one union delegates at the meeting committed to playing midweek matches during RWC 2015 in order to help achieve a better balance for tier two and tier three unions."
The World Cup's current format of splitting 20 teams into groups of five was endorsed but there could be a potential change to the tournament's start date.
New Zealand last month threatened to pull out of the 2015 tournament, claiming they cannot afford to put a team out because of the International Rugby Board's strict commercial regulations.
Monday's meeting endorsed the commitment to review the Rugby World Cup commercial model and revenue distribution.
While the meeting was not a decision-making forum, key recommendations will be put forward to the IRB executive committee and/or the IRB council for consideration.