A lot of people, and I mean a LOT of people, misinterpreted Shadow 05's last story ending. The ending is Shadow fulfilling Maria's wish and searching for his own path rather than living for just her.
He never erased her from his life, his memory of her and her promise is still part of his core motivation. His loss and grief for her never vanished, he still has lingering guilt and attachment.
Shadow Generations makes this even more clear when Shadow encounters a time-displaced Maria. His very first thought was how he can change her fate. He didn't ignore her nor did he push her aside with some "Damn, I don't really care." mentality.
In the end of Shadow Gens, Maria herself would tell Shadow to let go, that his "friends" need him. It's not a modern repeat of Shadow 05's ending, it's Shadow gaining more closure, he had already chosen to live in the present.
Shadow Generations' ending only shows how deep Shadow's love and grief for Maria has ran.