Kidani is going first so for Nov and Dec, Jambo will have no refurb taking place.
As far as room availability goes, what they usually do is block out a group of rooms just before the 11 month window begins that will be out of service for any particular time during the refurb, i.e.,
DVC has many months ago already classified some rooms to be out of service for times in Nov and Dec and has restricted reservations to the rooms that will still be in service at the time, and any rooms expected to be returned to service during that time after being refurbed
With the refurb not starting until Oct, you can assume that the majority of rooms at Kidani will most likely not be finished by early Dec, and getting an already done room is a matter of luck.
Nevertheless, you also have another issue for late November through early Dec 2025 if you do not already have a reservation.Traditionally, the first week of Dec has been the highest DVC demand week of the year at WDW (Christmas week comes in only as second highest). Thus, particularly with some rooms out service for refurb, even finding a room open now for multiple days during that time is highly unlikely -- currently there are no rooms open at Kidani, in any room category or size, during the entire first week of Dec.
I have been in Kidani twice when rooms were being done. Neither of those times had any noticeable decrease on being able ro see animals from a savanna view room that was still open. There can be some noise factor for rooms that are directly above or directly below ones being worked on at any particular time of a day, and that may be a little more noisy this time if, as I suspect, they will be removing portions of walls to make way for pull down Murphy beds.