As far as I'm aware the last few seasons it's been presented in Round 26, to avoid any potential embarrassment of presenting it post-game after a first week finals loss (which has happened twice in the last four years).
Either way, Melbourne are hardly in a position to be dictating how the NRL runs itself.
The Masters article I read is that the
NRL approached the Storm and asked for their preference as to when they want J.J. presented should Melbourne win the minor premiership. Ron Gauci told them his preference is that he wanted it done at the first home final and the NRL agreed to this.
If it was presented in round 26 it would be a travesty as it would be done in front of a very sparse crowd of Roosters fans (let's face it; the fact that they have not/are not doing well guarantees that very few people will be there).
Melbourne fans have been through quite a lot. What better way to start the healing process than to present something quite significant in front of a parochial Melbourne crowd?
Furthermore, the team has worked hard to accomplish the MP and earn a home final. They deserve to have this feat acknowledged in front of their home crowd along with all their mates who do not have the good fortune to be selected to play in the finals. Can you imagine if the Broncos won the minor premiership and had to have it presented in Sydney? The outrage north of the Tweed would be deafening.