I can appreciate that it may be sensible to discourage brothers and sisters from donating clothes and food. Whilst these may be needed it is better to buy supplies than deal with sorting and moving items that may be inappropriate for the needs of those people in the disaster area. However to request that no one can specify what their donations are for is problematic. Often the society downplays a situation based on the number of witness affected. Donations for the worldwide work are used to further preaching so there is no requirement to divert these funds for relief, in fact it goes against the stated purpose for this money to be used in this way. The society would have to set up a separate fund and have the congregation vote on it to be able to use money for aid. There can be no expectation that any money will be sent to those in need.
What will happen is a few will donate time and resources and then these individual efforts will be packaged up as a response from the society. It is sad that any religion can be so deceptive and inhumane.