For those that may not remember, I'm an accountant.
My first reaction to this was "so which is it? Are congregations independent units, or is the WTBS one big corporation?" The answer to that question has big ramifications either way. If they are going to put all the money into one big pot (which has certain advantages) they may be breaking down any wall that they're attempting to construct between HQ and the congregations. If they want to keep the congregations as separate entities they're creating a LOT of book work to keep track of which funds are where.
Since the legal dept was no doubt involved in the writing of this my guess is that they can't keep up the fiction that congregations are independent entities. If problems (read lawsuits) are going to swim upstream no matter what, consolidating funds to handle the problems makes sense.