What is unusual about PD marketing? They announce an initial release date 6+ months away, give a big blowout of info as they do then promote it up to release. It usually gets delayed, but that's also very common.
Anyway there is an obvious factor here you're missing. Pre orders. The pre order business is huge these days,ccompanies want you to be able to do it as soon as possible and are throwing more and more incentives out to do so. It allows them to judge demand and make adjustments based on it. Why would they miss out on the usual 6+ months of pre orders just for some pointless surprise factor? They could be selling thousands of copies right now, but instead people are spending their cash on others titles.
AAA games do not release within 60 days of their initial release date announcement, and with only the same amount of promotion. You can keep claiming precedent doesnt matter all you like but it exists for a reason.They just don't. Keep hoping and dreaming all you want, but GT7 is not releasing in 2020.
Preorders are more important in new games(new ip) and in companies with less resources, etc
Games like GT don't need that that much, it keeps selling a lot along some years (in part because of new free content updates).
AAA games can make a creative and different way of that usual planning when they are very well known as GT.
There is not an only way for making marketing
Creativity and surprise factor are very important too, not always doing the same than others.
And 2020 is not a common year, there are problems with that and creativity and surprise can fit with a 2020 planning problem too.
I'm not hoping nor dreaming, just not as rigid as your view