Not only will the new game likely be more RPG based like it's two predecessors, but the main character (named Eivor) will be very customisable...
Is Eiover a male?
Yes and no... Eivor the protagonist and main playable character in Assassin's Creed Valhalla is a 'Viking who participated in the Viking raids in England.
The name of your character is always going to be Eivor, however, you can choose their gender - presumably, this means, just like in Assassin's Creed Odyssey you will be able to play as a male character.
However, unlike the previous game, the two characters aren't long lost twins... but are in fact just the same character! Rather like 'V' in Projekt Red's Cyberpunk 2077.