I did read the article. They say that 10 to 20% of people do not even complete the first achievement in Forza Horizon series, which is drive the Viper in Horizon 1 and the Huracan in Horizon 2.
Based on that, you drive the Centenario in Horizon 3 for basically the same amount of time. It is the same thing, really. Difference starts where you change the Centenario to an off-road truck, and then you race an off-road buggy, then you get back to Centenario only then to choose your car. Horizon 3 has the longest "intro" of them all, and if people did not bother to complete the previous intros, i don't think that would change in Horizon 3. But will they say that in the article? Of course not.
They also said that they looked to remove loading screens, and yes they did, now it's just pitch black. :lol:
To be clear, i am not saying the game is a complete garbage, but this article is just marketing. As far as i can tell.