It was established in SJA, yeah, but not in main Who. They aren't really gonna rely on that when it comes to references. Which is a bit of a shame because you get more references to classic who on SJA. And even with SJA taken into account, Rose was the last companion he saw kinda like.... making sure something you really love is the last thing you see before you die, or holding that image in your head sort of thing.

I'm not saying he hasn't been close to others, some more so than others. Some like Jamie and Susan I tend to think he was very close to. Susan cause she was family, Jamie because he was, well, Jamie. And whilst I don't think he ever stops loving them I do think the pain of loosing one probably starts to lessen with time and regeneration, and the loss of Rose is closer and rawer than the loss of the others. There is Donna but their relationship was different and I think that's a different sort of pain, and a different sort of dilema.

It was New Years, yes, but it was a singular day, one celebrated every year and it is around the season and besides, the question wasn't so much about which Christmas Eve you choose to spend that last day with your loved one as it was how do you choose which day is your last? Any day, but the last day.