What i understand from the ending is; Mei & her mother get on that boat, go to a safe place. They meet Adam's (protagonist) wife & daughter there, you know they left the city in the beginning of the event. And his wife turns back, looks for him and bam, he's dead trying to find them. She finds the camera, watches the story.
I believe there will be an ''I am Alive 2'' and we'll play as his wife who seeks Adam. Or maybe a short DLC which explains how Adam dies.
Maybe the name of game is specifically chosen ''i am alive'', maybe Adam is still alive