Supposedly, this vindicates Comey. It justifies him doing all the things the Rosenstein letter says he should not have done. Incredible. If you get news your boss is going to obstruct justice, then that justifies jumping in and obstructing justice so your boss doesn't have to.
If he doesn't find the document credible, then it and the news reports are immaterial. All breathless over another piece of made up trash/fake report sort of stuff any consumer of information finds and discards.
It vindicates Comey under the "I was too stupid to know what I was doing" doctrine that has worked so well for Hillary, Sandy Berger, and other Democrats.