I think heroes need to die in order to establish that Obito is a threat. No more of this he defeated the heroes but left them almost dead only for them to recover later ****. However, thanks to Neji's deaths, I think another death for Naruto's friends is unlikely. If it does happen, it will not be Hinata but probably one of his masters, like Killer B. Again that is unlikely.
I think a far more likely death would be Juugo. Sasuke has not lost someone since Itachi. Thus, I think he will be the next character to lose a precious person.