This article states that Agnostic Theism is much less common than Agnostic Atheism without providing evidence to support that position. Since scientific surveys of people's religious inclinations (or lack of them) rarely collect this level of granularity, it is doubtful that there is any reliable evidence supporting which of the two varieties of agnosticism is more prevalent.
Also, stating that "...perhaps because Occam's Razor provides a persuasive argument that..." is a subjective statement that many would dispute. The phrase "assuming the nonexistence of a thing... 'default position'" inaccurately represents what is commonly called Occam's Razor. It would be better to phrase this statement, "...perhaps because many Agnostic Atheists believe that according to the principle of Occam's Razor, nature and natural phenomenon are better and more simply explained without attributing the existence of nature or its phenomenon to a god or gods."