This is the right call, let the people of the NASA focus on what is really important, and not waste time on PR.

It's pretty obvious that the people who managed to extend the lifetime of Voyager are very smart, based on all the tricks they had to do.

They are remotely configuring an old-tech device that is billions of kilometers away, with insane lag, and uncertainty that the underlying hardware is even responding properly.

Absolutely anything could have go wrong at this stage.

They'll anyway investigate internally what is going on, in order to hopefully, find a solution.

There is no need to spend resources to make the material public, just to satisfy curiosity (though it's interesting).

Does this assume the information is made available, but just not as polished as PR?

As a spacecraft navigation engineer, I guarantee you said post-mortem is already being written, and is probably going to be posted "publicly" anyway on some deep corner of the NASA website

Asking for a post mortem is not too much to ask. This is the bare minimum for operating serious craft like this.

There's a difference between a post-mortem and a public post-mortem. Nasa is pioneering technology that shouldn't all be public. If you really think the same post-mortem would be published in public and internally, you should not be commenting on HackerNews because it's forbidden below 13 years old.

It definitely got written up internally. Making it public is just a matter of taking that, sticking it into a pdf, and hitting the publish button. A few hours' worth of additional work at most.