You mean perfectly logical.
That is not logical because it's like saying EA doesn't make money on properties in the region. Even as speculation for deals in Japan. At the very least they wouldn't assert the entire volume of PS4s as a function of their business. Unless they are really taking active consoles into account. You can just make sales disappear from someone else's count.
EA has excluded Japanese console sales before, so concluding that they are doing it again is not a stretch in the least. It is the most reasonable conclusion to make, because that way all the numbers add up.
The only thing left that's questionable is their estimate for 2018 sales (27m combined between PS4 and XB1), but they might just be very confident that both Sony and Microsoft have an official price cut on all SKUs this year and great holiday deals again, ultimately leading to only a slight decline for the PS4 (17m compared to last year's ~18m; remember, Japan is excluded) and an increase from ~8m to 10m for the XB1 with the expectation that the Xbox One X helps in 2018 like the PS4 Pro helped the PS4 in 2017. It's not an impossible forecast, but it's clearly on the optimistic end of the range.