I will try to have more specific information this week (if I must go to the meetings...)
I remember they said that everybody with monthly money transfer to the local bank account must see the accounting attendant (not sure of the name in English) to change the destination. The global account is titled something like (translated from French) "JW Kindom Hall Federation". So it seems that there won't be any local account anymore, although I agree I don't see how it will work for current expenses. Or... maybe the money goes to the global account, but the cong will open an new (and tiny) account to get some "pocket money" for the current expenses.
The explanation was quite the same as Hoffnung shared. But no resolution was adopted, it was just an announcement (but maybe the official representatives of the legal association will sign a resolution in private).