In my opinion this is the perfect opportunity for Yu-san to do his original vision of the story, and i think he will do that, it is confirmed that we will see things that was cut in the games, right? i think we will see the boat chapter and maybe the train chapter, maybe we will even see some scenes days before Iwao's death. Ryo hanging out with his friends, more closer to Nozomi, this Ryo is a little more happy. In my opinion will be really interesting to watch this scenes in the first episode.
I think we will have some scenes after Iwao's death, scenes that are not in the game, people going to Iwao's funeral, maybe we will even see Ryo crying, imagine Ryo alone, he is sad and angry, he is in the rain, and in one part he says "Lan di, i will find you and kill you, i will avenge my father" something like that and with a sad song, i think it could be really interesting, maybe the first episode will end like this.
It looks like the anime will have a more mature tone, i think it will have a mature tone but we will see too funny and cute scenes, maybe in the anime we will even see Ryo and Nozomi kissing, who knows? haha. Maybe in the anime we will see more about Mark's brother. Maybe the plot in Yokosuka will expand, maybe the story of the first game will be 5 or 6 episodes.
So many possibilities. All i know is that i'm really excited for the anime.