Apparently, a number of characters, including major names like Nicole and Mercer, and even minor side characters like Jacob Temple and Elizabeth Cross, have had their roles significantly expanded...according to Dead Space “realization director” Joel MacMillan some of these characters will have full-on sidequests devoted to them, which will give you new insight into the destruction of the Ishimura...
https://www.ea.com/en-ca/games/dead-space/dead-space/news/inside-dead-space-5-story-matters
https://www.ea.com/en-ca/games/dead-space/dead-space/news/inside-dead-space-5-story-matters