Since they’re a public institution their decisions are published for anyone to look up, read, and understand the rationale behind their decision.
It seems NYT got the scoop on this particular case but you can expect the decision to be posted on the NLRB site when it’s finalized. I suspect the NYT (and the person who tipped them off) does not yet know the reason for the Board’s decision. It’s very likely no one involved in this article has read the document yet and, for now, they’ve only been informed as to the outcome. NYT, Amazon, and the aggrieved parties will probably have to wait to read the Board’s written decision along with the rest of us.
> now disproven legal theories
Disproven? According to whom? The whole point of the press is to show its work to the public. Maybe you're correct that it's disproven! But I would have no way to know how/why it's disproven as a NYT reader. Anyone that wants to demonstrate to voters that Amazon's legal theories are disproven needs to show their work.
Maybe after presenting all sides of the decision, an NYT reader might agree that the NLRB's decision was correct/valid; but with the way the article is written, it's impossible for that to happen.