Yes you would be right I haven't taken a class on analytic number theory. Perhaps excuse my lack of knowledge on the subject but why would psi(x)=0 for x in [1, 2)? Λ(2) is not 0. You are right that arXiv moderators don't review papers in the sense of peer review but they still check over them and I haven't heard of an occasion where something that was originally placed in General Mathematics or General Physics was later moved to another category. Safe to say if there was anything substantial in the proof we would have heard of something from the experts in number theory by now.