Yes, I believe that the extra bathroom is going to be in Kidani only for the 1 and 2BR.
The Jambo GV we stayed in two weeks ago did have 4 bathrooms, so that had one more bath than bedroom, though that may be the case all at GVs, not sure.
There are a few differences between the 1BRs in Jambo House and those in Kidani Village. The Jambo 1BRs are smaller than those in Kidani and have one bathroom. To move between the master bedroom and bathroom, you have to cross a small open hallway. This has taken a few people by surprise since in other DVC resorts you can move between the bedroom and bathroom without being seen by someone standing in the kitchen -- not so in the Jambo House 1BRs.
The master bathrooms in Jambo House have a combined whirlpool tub and shower except for some of the HA 1BRs which have a roll-in shower instead of a whirlpool tub. The master bathroom in the Kidani 1BRs will have a whirlpool tub and a separate shower stall, as is the norm in other DVC resorts. The Kidani 1BRs will have a closet in the master bathroom whereas the Jambo House 1BRs have a wardrobe in the master bedroom.
Here is a floor plan for a typical Jambo House 2BR lockoff. The two bays on the left are the 1BR, the bay on the right is the studio. Not every 2BR lockoff in Jambo is laid out exactly like this one -- some have the connecting door between the 1BR and the studio in the living area rather than near the main entrance, for example.