Note that it's not a "per review paper", it's just a PFD shared somewhere, a "preprint" if you like a formal word.
It looks short (4 pages) and looks quite readable, so I guess that if you wait a week or two it will be a major new IF true.
My guess is it's false. It looks like the author made a similar claim two years ago and it's now fixing some details. With a loooooooooooooooooooong proof that is possible because only the author can understood it good enough to fix it, but with a proof that is so short a minor error would have been fixed soon.