They can't do just Studios first because the Studios are interspersed with all the other room types. What they'll probably do is like Kidani, they'll close off one wing of the building and refurbish all those rooms, working their way from the lobby out, and open sections as they can.
The Club and Value rooms are separated from the main 5th floor rooms so they could follow their own refurbishment schedule, and it appears that they may be (or it may just be that they are being heavily walked for Christmas, which honestly is pretty typical for this time of year).
Booking Jambo before the end of the refurbishment means you may get an old room. So if you really want that murphy bed, I'd recommend you book Kidani until the refurbishment is supposed to be completed.
It's also important to recognize that
DVC didn't promise every room type will get murphy beds. The Value Studios and 3 bedroom grand villas may keep the sofa for example, we'll just have to wait and see.