Hi MWB.
If the people who want the existing organisation wait until a decision has been taken, they might end up trying to persuade the DHB to withdraw funding from the new organisation (which has been allocated future funding) and to give it back to the original organisation. Such a campaign would seem to be almost doomed to fail (because it;s extremely unlikely that the DHB would reverse a decision) and it would also create great ill-feeling from the supporters of the new group (which might be equally, or more, deserving).
So it makes far more sense to try to bring pressure on the DHB before they've made their decision.
As an analogy, let's suppose that your neighbour plans to build an extension to his house, which will block out your light. Is it better to write to the planning authority straight away, before they've considered your neighbour's application, or to wait until he's got permission and built his extension? The answer seems obvious to me.
Chris