I have spoken in the past to a member of the WDC I know and have formed an opinion based on things those conversations.
Over the past few years the org have been undertaking a large scale reorganisation and have employed various consultants to develop strategies. They also had a very open policy of encouraging out of the box thinking where nothing was off the table.
In terms of construction this was being manifest in large scale expansion of branch facilities, development of regional translation offices and the idea of a global approach to KH construction. The new halls would portray a different corporate feel and (reading between the lines) offer a more attractive proposition to commercial buyers in the event of resale.
The big problem was that the RBC was full of chiefs and a whole bunch of keen but essentially low skilled workers. Quality control was variable. Congregations would go off plan or local purchasing decisions would reduce the benefit of economies of scale. Some of the branch construction works were showing the value of having full time senior team members and employing outside contractors for part of the works.
Bringing the whole thing to the WDC/RDC/LDC hierarchy has forced a centralisation of ALL construction globally. In conjunction with this the WT made a money grab to not only generate cash assets but also force what should be autonomous congregations into a relationship where it is impossible for them to go off plan and do something themselves. It also brings economies of scale into the operation, which was already there to an extent, but is much more centrally managed now and undertaken by a small procurement team.
The change to the RBC was done under the fanfare of a massive building programme but this was then dealt a blow by the concurrent change to financial approach of the organisation. Literally overnight hundreds of projects were cancelled. Hundreds, if not thousands, of full and part time workers were told they were surplus to requirements. Entire teams both in the field and at Bethels disappeared in a day or two.
The upshot of that is that the scale of the work can now be easily hidden since far fewer people have the inside track.
The RBC went because the GB wanted the US to have control of construction worldwide. It happened prior to the construction downturn but the organisational change suits the way things are now so the GB ain't complaining.