So, something that is a pattern since some good time now, is showing games way in advance to their releases, while it's nice to see what we'll be getting asap, and creating hype asap is also good for their companies, do really announcing games more than 1 year away to launch is really the best thing to do for the games itself?

Look at this E3 for example, we had the new God of War announcement, without a release date, and even as it's better than a false one, I'm really happy at least this is already changing, do showing it now is the best choice to make the game sell the most it can?
If you look at the PS channel GoW announcement video alone, it's already around 8.5M views, the hype of a new big game annoucement is very clearly doing well for Sony and PS because they are being talked about right now, as the other companies with their own games, but now let's look at Horizon.

Horizon was once again at E3, being announced during E3 last year, it's own new trailer on the same PS channel has WAY less views than the new GoW one, and even without taking in account it's a comparision between a very acclaimed series and a new IP, compared to what Horizon own announcement trailer views it's also way lower.

Now, consider two things:
First, 8.5M views for the new God of War, none of the game in the series has sold that amount of copies (I'm not telling views = sales, just have that in mind). Second, Horizon even having a superb showing, has it trailer getting way less views than last year.

So, to me it seems pretty clear that hype explodes when something is announced, which is no news, and looking at that single GoW video having more views than any game in the series has ever sold, it's pretty clear that are more than only usual GoW fans paying attention to it, and that after this hype goes away, even with another great showing, like for Hoziron this year, there is just no reaching the same levels as it once was when it was announced.

And what I want to take from it?
Simple: Wouldn't be better to make use of this huge hype explosion, to actually sell the games, and not only promote them?

If GoW was coming, lets say, in September/October, don't you think it would have a better opening than it may have launching next year, when this initial hype has already gone? That the people hyped for it would want to get it asap after having saw it?
Same for Horizon being released last year.

It seems to have worked pretty damn well for GTA V, in 2013, everyone was talking about it, and it came not that long after it was announced and the hype didn't have much time to go away, it was heavily marketed and sticked into lots and lots of people minds, making up stellar sales for the game even considering the own huge series sales achievements prior to it.

So, there are lots of other factors to consider, as consolidated series, like Uncharted, can and will sell well anytime of the year and even with more than one delay, but don't you think that developers and publishers should keep their hands closer to them and make a better use of this hype to boost their sales? Or do you think it won't matter when it's announced to when it's released and it'll perform similarly anyway?

IMO, people, as consumers (and even as not), are very guilable, and marketing teams are very aware of it and bombarding people and making them buy more and more stuff, but it seems to me that even so, game companies are still missing a good opportunity to make use of the very known hype with their games announcements and actual release distances, and even as pre-orders are a good make up for it, hype makes lots of people go and pre-order games asap, I still think sticking to announce and release your game closer than later is a better tatic that let this initial, huge hype, wears off for some people because the game is still to take its time to be released.

What is your opinion?

The thing is, they would always have game to show, because if they didn't show 2015 during 2013 E3, they would show it at 2014 or 2015 E3, and 2013 E3 would have them showing games for 2013 and 2014, but that they showed 2012, they would always have games to show, because the number of games don't change, just the time they decided to show them.
It'll be kinda of a punch to take, if changed now, as it already snowballed, so the year they decide to show only the close stuff, it'll be mostly stuff already known about, and it'll do little for their hype push, but the next years they'll have as much games as before to show and to release following, it would end the snowball effect and we would be as excited as before for the next E3 because we will have new games being unveiled, but that are just closer to release now.