It ends up they are not the same Matthew, but Matt D. was kind enough to write me a detailed critcism of Drange's essay. I will take the liberty of quoting a small section of his e-mail here with regard to the proposition "God Exists" (ignoring the first option of noncognitivism):
2. The individual accepts the proposition
3. The individual does not accept the proposition.
Note that this does not mean that the individual accepts the contradictory proposition. That proposition is separate. I do not believe that any other option exists. Someone can BE noncommittal, by refusing to state what their position is - but they either accept the proposition or they don't. There is no other option.
So I will continue to use "atheism" to mean "non-theism", because that term is more useful. I also think it is more politically expedient to make atheism an umbrella term including all non-believers.