(I agree that the the thinking is incomplete but disagree on the detail regarding in which sense the thinking is incomplete.)

I currently do not wish to be wireheaded, but I'm uncertain whether that aversion will turn out to be coherent. A technique for preventing AIs from wireheading has not yet been discovered, and there is no proof that one exists. So in that sense LW's thoughts on the subject are necessarily incomplete.

While proving things formally about something as complicated as AI is hard it would be misleading to act as if this makes the question "is it possible to have AIs that don't wirehead" at all an open question. The probability that such an AI is impossible is sufficiently small as to be safely ignored. Objective functions which wirehead are fairly obviously just a subset of objective functions which optimize towards any arbitrary state of the universe. That paperclip maximisers could theoretically exist is not something that is an open question on LW and so therefore it would be rather incoherent for LW to have much doubt whether something in a far broader class that includes paperclippers could exist.

Where the thoughts are actually more complicated and in doubt is in regards to what humans in general or ourselves in particular actually want. Introspection is far too uncertain in that regard!