Completely the right decision in my view to come back tomorrow in the SF. Unless they could be 100% certain that rain wouldn't interrupt the 20 over Indian reply (which would have meant coming back tomorrow to finish off their 20 overs), it's better to come back tomorrow to finish off a 50 over game. Use a reverse day to finish off the match properly (unless it rains tomorrow), rather than use it to finish off an already reduced match.
What interests me is the decision to come back at 10.30 tomorrow. An exact like-for-like would have seen the game restarting at 2pm tomorrow. Rather than an afternoon/early evening run chase, India now have a morning/early afternoon run chase. That might just favour NZ, if a wet night and/or overcast morning can lead to Boult getting some morning swing.