Seems like they're preparing a new part of Time Temple.

I have to disagree. I think that Freed is in the trailer, and that fight is before they were sealed up. Just like the Demon Slayer trailer, where after his family is killed he goes to confront him. All of those trailers seem to be Pre-Black mage sealing up fight.

However, I'm gettin a bit confused how all it went. The 5 heroes went to fight the black mage in that amazing Leafre fight, where Freed, the most powerful mage of all times according to the storylines ( Yes, the story says that Freed was looking for a way to become more powerful, and then he alliance with Afriend to fight and stop evil.) sealed up the black mage while the other heroes were "distracting" him.

But in Mercedes storyline, Freed is dead and already hide the egg, I mean like what? The battle should have happened that same day, and left the 4 heros + Afrien being sealed by the Black Mage final attack.

Mercedes was unconscious, Freed probably didn't bother to look for her. He'd have enough time to hide Afrien's egg, die, and then be found by Mercedes.

I still don't get why you continue to doubt that it's Evan, though.

now why would you assume that?

They've done it before.

It did happen. Have you seen what happens when you create one Demon Slayer?
You spawn in the Temple, and get into a Black Wings reunion, you get to see the generals, and then you spawn in a burning house. You click on 3 different places, then click at a small locket. You find it, and it shows a cutscene of the Demon Slayer looking at the picture of his mother, and his brother Damian.

He then, looking for revenge, comes back to the temple and fights the black mage. Then he loses the battle, and is sealed inside Leben Mine. J finds him, and takes him to the Resistance. The "promos" aren't only promos, they are cutscenes too.

The promo art you showed up shows Freud, not Evan. See the girl next to him in the first image?
As you posted an image of the player being transformed into Freud, you should also take a look at the level 70 quest for Evans.

You go to the lost cave in Rien, and then Afrien says he will show you what happened in the past. If you're a female Evan, you'll be transformed in the past Hero, the female version of Freud, that would fit the story when Mercedes is a male character.
The girl in your screenshot IS the girl Hero, meaning the other guy is the male hero. Freed's blonde, but has a light brown hair colour in that trailer, although inconsistent, Evan's hair is dark brown.

Make a new evan character, and pay attention to the cutscenes, and the images of the boy and girl. The girl has a VERY different hair compared to the first image, and the boy has a dark brown hair.
The promo image you posted shows the Hero, the master of Afrien, in both male and female forms.

Really, people should stop trying to assume things without reading, or looking at it in game. You know, those videos can be more than just random ass action for new characters.

Then why is the cash shop set that's featured in the trailer and the Evan release poster called the Evan set and not the Freed set? There's another robe that matches Freed's in the JMs cash shop and is called the Dragon Master robe.

Also, it would make no sense for Nexon to feature Freud as the main foreground image in an Evan class release poster.