I think it fine to read preprints before peer review. Peer review is not some panacea to bad research of course. This work is at least interesting, to me anyway, if short of compelling "proof", it's another link in a chain perhaps. And it's possible the studies are flawed, but peer review often cannot pick up on that.
First, it was dismissed because it was cited by CNN, and now because it isn't peer reviewed. Neither carries any water for me personally. I have done peer review, I have some understanding of how flawed it can be.