Samuel Herd made a statement a few weeks ago about halting construction work, laying off bethel workers and reducing printing output: severe cutbacks all round. He said, like the head of a household, the GB has to make sure the organisation is living within its means. But he added a very careful phrase, something like: "be assured brothers these measures have not been taken as a result of any lack of financial support on your part. You have been very generous."
Having read a couple of books by Professor Cialdini on influence I understand that social proof is one of the biggest, probably the biggest influence on human behaviour. Basically it means humans "follow the herd", look for clues as to how others are reacting to a situation, and do likewise.
Maybe the GB are aware of this very important influence on human psychology and it informed their carefully worded statement. They realised that if they said donations were down or financial support was disappointing, psychologically this would be received as a message that other Witnesses are donating less, and probably therefore I should donate less as well. Or even: why should I donate more if everyone else is donating less?
So, even if donations are down, and the GB are worried about that, they might feel they had to pretend donations are keeping steady, in order not prompt yet further falls in donations by generating unhelpful "social proof".