I just want to point out a couple of things:
1) AK is, for the most part, a zoo that features animals from tropical areas. I don't know of many zoos that are open past sunset during the winter. It's colder, and the animals from tropical climates need to to be inside when it's cold. Now, Florida cold may not be Massachusetts cold, but it's still colder than it is most of the year. The days are shorter, too. AK would be no different than most zoos around the world if they decided against night time activities that time of year. So planning for night activities at at zoo in winter might not be the most judicious use of your time. Weather is the reason that most of the attractions are inside, because a roller coaster when it's 45 degrees is not pleasant. But since Ak is about nature, that paradigm doesn't work as well; as a result, the park is a lot more dependent on nature than other WDW parks, and therefore much harder to anticipate and plan.
2) If you need to plan, plan for what you know. If things change later you can change them, but plan for what you know, rather than for what you wish/hope. I've never seen a situation where WDW reduced from previously published hours. For AK in the winter, I imagine the decisions will be made in very short time frames, because they need to be cognizant for cold fronts coming through. I wouldn't be at all surprised if those hours never go past 7 once they get into November, so I think you will be in for a long wait if you want to know when AK winter night hours will be.