People have this misconception about Halo, they call it a huge system seller, but when you look at the numbers of actual hardware that it moves upon release it's not actually that high, not compared to something like Destiny, Watch Dogs or say launch effect or the effect of multiple reasonable simultaneous releases.
Looking at the 22nd of September 2007 (according to VG) 360 already sold 164,012 that week, Halo 3 comes out on the 25th of September and yeah it moves 3,811,047 software units by the 29th, but the hardware sales only go up to 11,902,194 from 11,670,655, that's only an increase of 67,527 consoles sold because of Halo 3, the best selling Halo game of all time.
It seems most likely that anyone that wants to play Halo will have already bought an XB1 by the time Halo 5 comes out, the series seems to be on a downward trend in popularity. It's very doubtful that Halo 5 will even have a fraction of the effect that Halo 3 did on moving hardware.
Forza has already had it's effect with Horizon 2 and Motorsport 5 already on the platform, Tomb Raider isn't an exclusive and recently it's been heavily rumored that Rise of the Tomb Raider will be on other platforms by Spring 2016.
No doubt Halo 5 will sell a high volume of software, at least a couple million week of release, but I don't see that alone pushing close to a 60K boost compared to the week before it releases.
