From what I have been seeing tracking Aulani, its highest demand time of the year is mid-June through early July. What many have experienced for that period is seeing the time they want still open just before 8 a.m. at 7 months out and then when they try at 8 a.m. eastern, it is gone for at least the first day they want. That is an indication that the room category they want has only a very small number still avaialble and they are just losing the race of whose computer speaks first to Disney's computer at 8 a.m. It is a time of year when all room sizes can potentially have issues but sometimes you can get something, with a somewhat better chance in ocean view than others.
The rest of the summer therafter is problematic but still chances of getting things although it may require date or room category fexibility, first two weeks of Aug are harder than others, and standard view and the hotel are almost always gone. Other than standard view, demand is not necessarily tied to a pattern that lower point rooms are harder to get than higher point as sometimes pool and even coean view are gone before island garden, sometimes ocean view is gone before pool view, and sometimes 1BRs and 2BRs are gone before studios.