and JRPGs are the smallest genre these days if we talk about mass appeal
even racing games are bigger. and according to many that genre is "dead"

this game will not sell 4 - 5 million in less than one week. 
not in the year 2016

if they want to come anywhere close to 10m, they need to sell many copies in china and asia on pc and consoles.
in other words. get a new audience. 

The lowest Selling games of the franchise sold 1.9 Millions Within 1 month after Release just on Japan, how the game will not sell 4-5 Millions in 1 week ?, i bet 2 Millions Japan, and 4-5 Millions Worldwide for the first week (i Mean Out-side Japan, so 6-7 Millions First Week Worldwide).

JRPG, are one of the Strongest Genres out-there, with the best selling franchises, Pokemon, is a JRPG, Dragon Quest,  that is nearly Japan Exclusive, sold 65 Millions of units, Final Fantasy, aways was exclusive to 1 console until FFXIII, and sold 110 Millions in just 30 Years, Halo, is  15-16 Years Old, and sold 65 Millions, Gran Turismo, is 18-20 Years Old, and sold 75 Millions.

Racing, and Fighting games are less popular than JRPG Games, but they both hold well, does not need to be the Biggest Genre, to be successful, Survival Horror, also isn't a big Genre, but is a Sucessful genre.

You seems to think that only Shooters, sell, but that isn't true, even some Shooter struggle to sell something, Call of Duty, Fifa, are 2 franchises with Loyal Fanbase, those are Exceptions,  they hold a fanbase, but does not hold a good level of Quality, because the Companies that own those games are milking the Franchises, GTA, is a exception, is a High Quality game, the Mother of Open World Sandbox, and each game sell more than the previous, because they praise Quality, GTA's Model is what Developers need to follow, make games within their  own genres, and make Quality games.

4-5 million in less than one week? games like Assassins creed, even its peak didnt manage to sell that. JRPG isnt a big genre, not anymore and it hasnt been for a long time. if you honestly think it will sell 4-5 million you are setting yourself up for a massive disappointment. 

its doable. Remember the game will do like 65%+ of its lifetime sales in Japan week 1. So if it only sells like 1.5 mil there that is close to 1 mil week 1. To get to 4 million it will need to sell 3 million on both console in the rest of the world. I think it could do over 1 million on the PS4 in NA alone. 

I would not call it the biggest, Pokemon is bigger. 

I have to say I didn't account for a far bigger Chinese and Latin American marktet. I think they'll be the deciding factor (especially LA).

Pokemon, is the biggest in the Handheld, Final Fantasy, in the home console market.

Just because something is on handheld, does not mean that gaming wise it is not the biggest. You are right that Final Fantasy franchise is the biggest jrpg in the home console market.