It's worth remembering that the Nikki death was meant to be just out on a random run, it didn't matter if you were on her path or not the run was a canon event and she was meant to be ran over, that would have come out of nowhere if Nyx had gone through with it and it would be easy to set up any kind of canon event like that with any character at any time. And for cases where you have little to no contact with the character anymore then the event could happen with or without MC present.