Your memory has failed you, then....

http://www.informationweek.com/halo-3-sales-smash-game-industry-records/d/d-id/1059689?

Microsoft did the same thing with Halo 3. Microsoft doesn't reports sales, thats npd job for north america. Microsoft doesn't have the ability or resource (although they could) to find the sales thats why NPD exsists in the first place.

"Retailers took more than 1.7 million preorders for the game, which runs on Microsoft's Xbox 360 console."

You missed that part. So, Halo 3 had 1.7 million preorders plus actual launch day sales on Day 1. That's much higher than what Halo 5 sold (and its sales spanned over more than 1 day).

How about their PR for Halo 4?

"Exciting news for the Halo team at 343 Industries and Microsoft Studios – critically acclaimed, “Halo 4” is now the best-selling Microsoft Studios title ever in the U.S. market*, surpassing its predecessor, “Halo 3” for sales during each respective launch year."

Pre orders does not equal sales (many people cancel preorders) and they didn't give out specific numbers for what the game sold. Also, unlike last gen, this gen digital sales are much bigger and are available day one.

Preorder do equal sales. Cancelled preorders do not make any significant statistical difference, so I'm not sure why you are making things up like this.

Digital sales may be higher than last gen, but Halo 5's physical sales are way, way lower than its predecessors. The digital rate needs to be over 50% in order to compensate for such a large drop.

Not doubting it. Just making sure people realise that digital is also big on PS. Sony have reported impressive digital figures in the past and the PSN store cards take a few spots in the Amazon top 20, usually taking the top 3 spots. When Uncharted figures come out, I'll be sure to remind everybody to add on 20%.

Preorder does not equal sales at all. People forget to pick up the game, they cancel the game, they ignore the game or sometimes they will buy the game at a later date. Also, Halo 5 physical sales are not way lower. It is around Halo 4 league (3.8 million) and if Digital and physical gets counted together is right there with it despite not having the userbase that was xbox 360 in 2012. 

Nintendo has released at least 7 titles this gen that will sell more than Halo 5. Uncharted 4 and Halo 5 will likely be rather close in sales, considering Uncharted's sales has grown for each consecutive entry, and the PS4 is the leading console this gen, while judging from what we know, Halo 5 has dropped substantially from previous mainline entries. I also wouldn't count out Gran Turismo 7 when it comes to outselling Halo 5.

Do you have a citation that proves that cancelled preorders make a huge difference? Yes or no? You have not provided any empirical evidence, so why make such a faith-based claim?

The rest of your comment reeks of ignorance. Halo 3 and Reach, for instance, sold 3.3 million physical copies in the US alone. 1.4-1.5 is less than half of that. The digital rate has to be unrealistically astronomical in order to compensate for such a gap.

What game are you talking about for Nintendo? Halo 5 will sale around what the Wii U sold life time lol. And talking abour franchise decline, GT 6 sold like crap compare to the rest of the series so who knows what GT7 will sale like lol.