I think this can work. For starters ANZAC Day 2015 is a Saturday. The time difference between Sydney/Brisbane/Melbourne and Istanbul is 8 hours. So a midday kickoff there would be prime-time 8pm here, 10pm in NZ and 6pm in Perth.
However I don't see it going ahead. There will be a huge public backlash, sport trying to cash in on one of the most sacred days in our history.
Depends how they go about it. They can't schedule it on ANZAC day - everyone will be at ANZAC Cove/Gallipoli peninsular pretty much all day. It would have to be a day or two before or after ANZAC day. It would then form part of a week of commemorations.
Also, Istanbul is about 300km from ANZAC Cove... bit of a hike.
They would have to work with the RSL, Legacy, ADF, Federal Government, Australian War Memorial, et cetera. Any profits from it would have to be put towards a charity so it doesn't look like a marketing exercise.
A lot of people going over will be there to sight see around Turkey, Australians and Kiwis travelling across from Europe, and others doing battlefield tours. Australia will probably send a number of RAN ships to Gallipoli which will be used for state functions/commemorations.
If the game is scheduled on say 23-24th or 26-27th at midday in Istanbul as a prelude or follow up to the main event, it would work increadibly well. Get the Governor General and PM of Australia and NZ to turn up, RAN Sailors, RAA soldiers, veterans, Turkish dignetries and military presence.
The crowd would be mostly Australians and Kiwis there for ANZAC day/on holiday. I read somewhere they are expecting as many as 60,000 to travel for 2015.
Also, don't forget that the Gallipoli campaign was mostly French and Brittish soldiers. There will be a noticable Pommy presence for it, and it would be reasonable to expect some of these attending the game.
Around 25,000 paying tourists would be a reasonable expectation, plus say 3,000 ADF/NZDF plus politicians, plus Turkish defence/government personel... a crowd of 30,000 would probably be easily achieved.
But it has to be done right... hell, the NRL could even ask the Federal Gov to foot the stadium hire bill, and have free tickets available to those travelling in Turkey.
This event can't be about making money or even Rugby League. If done right, it will be fantastic.