I saw a comment the other day on this that I’ve been thinking on, paraphrasing it went something like:

This article is intended to send a message to North Korea. Several years after the fact they publicly release details of an operation that was arguably pointless in the first place and resulted in a massive failure on several accounts. The listening device wasn’t planted, they were discovered immediately and the ongoing nuclear talks quickly fell apart after this, and it’s unknown if those are related. If you’re NK you have to assume this wasn’t the only operation and that other attempts have been made, and if they aren’t talking about those failures maybe one was a success. So this could be the US signaling to NK via the NYT “We’re listening” to spread paranoia or signal they know about an upcoming plan.

IDK, personally I just read this stuff as them bragging like the ghouls they are.