From what I understand, they are removing the addition on the north side in order to do their seismic work, and then they are rebuilding it again. So for maybe a year or two you will get your wish.
It's curious that the temple wasn't originally designed with more sealing rooms (there are only 3 inside the temple proper), and it is also curious that more rooms couldn't be added below ground, where they wouldn't impact the aesthetics.
There are other things about this renovation that will be interesting. I immediately began worrying about all the people who will 'jaywalk' into North and South Temple streets at the new openings in the wall, since the old openings line up perfectly with the crosswalks. I predict some sort of barriers will need to be built, probably in the middle of South Temple Street (like fence between the TRAX tracks) and on the raised curb in the drop-off area on North Temple.
The two new visitor's centers on the south side look very small. I wonder if they'll have anything else inside them other than bathrooms and that model of the interior of the temple? I was hoping that the North Visitor's center would get a complete renovation. I don't think those huge movie theaters they have on the west end of it are a good use of space, and overall it seems like such a Hodge-podge inside. It will have to happen some time, but I guess it is wise to stage the renovations so that the new south centers will be open before they touch the north one.
Also, has the Assembly Hall ever been seismically updated? I know the Tabernacle was completely rebuilt in 2006-07, but I don't think the assembly hall has gotten as much attention.