“I don’t expect my own environment to be random noise, but that has nothing to do with witchcraft...”
I think I misinterpreted the math and now see what you’re getting at. Would it be an accurate translation to human language to say, “a sequence like 10101010 may favor witchcraft over the hypothesis that nothing weird is going on (i.e. the coinflips are random), but it will never favor witchcraft over the simpler hypothesis that something weird is going on that isn’t witchcraft”?
I find it awkward to think of “witchcraft” as just a content-free word; what “witchcraft” means to me is something like the possibility that reality includes human-mind-like things with personalities and with preferences that they achieve through unknown nonstandard causal means. If you coded that up, it would probably no longer be content-free; it would allow shortening the rest of the program generating the sequences in some cases and require lengthening it in some other cases. In all realistic cases the resulting program would still be longer than necessary.