Wouldn't an 'absentheist ' by your reasoning ,be someone who believes that the god of creation..is absent , therefore must have at one time been ' present '.
Reminds me of the ' god is dead ' claims of a few decades ago ie god once existed . It seems to me that people who once believed in god who have come to realise through critical thinking now doubt god exists still have a fear of absolutely concluding that the theistic god is a man made concept, and come up with the type of op which you have presented. It really is circular and says nothing of substance. The fact that you resort to trying to give the example of a sun god which does not relate to being an absentheist as you see it , bears this out imo.