Ol' Moe, dead as a door nail, eh?
I've never understood how the "Moënghus lives!" theories get past the clear evidence of his death-by-Chorae. But as a way to while away the early summer days, I'll bite: What's the case for a living Moënghus?
No joke, the death-by-chorae is explained as not-death due to the color Bakker used in the description of this scene.
This was (wrongly) guessed to be unique to only Moenghus, then later once quotes disproving that were quoted many times the theorizers said 'fine, all Cishaurim do it', then laterer (more quotes) 'ok it happens to everyone' but at this point they were fully committed to Moe being alive so it was mostly ignored.
Most other pieces of said Meta-Moenghus theories are either contradicted by pretty direct quotes from the book (room for speculation in some though), or rely on speculated mechanics which are so outlandish as to be entire un-provable and equally un-disprovable. Typically these are related to infallible super-powerful and entirely invisible meta-psuke magics which can be used to explain (literally) how Moe was behind every single happening in the entire series whilst remaining totally unseen. This conveniently also allows any argument to be dismissed outright (*handwaive* but meta-psuke can do that), thus rendering it an unassailable hypothesis.
But do please keep in mind we needed something to talk about for the 5+ years we waited for TGO and this single avenue of speculation provided many, many hours of discussion.