The reason I think communication is very important is that limited or incorrect / stale information is a very big problem for medium-large organizations (the kind of organizations that have PMs). Many times, poor or lack of sufficient communication is the foundational reason for other issues that we see regarding seemingly always changing priorities, decisions being made out of nowhere, etc.
It's all about aligning incentives. You need to reward PMs for getting stuff done, rather than looking busy.
So either the advice around those parts doesn't truly work, or the PM just wants to be seen to be visible.
An example: I'm meeting with a sales rep who has a customer pushing really hard for a specific feature. It might be a good opportunity to walk them through what the overall strategy is over the next six months to help frame where their feedback might fit into it (or to explain why it doesn't and why we're unlikely to work on it). I might have shared this a month before at an all hands, but I can emphatically say from many past experiences that repeating it is helpful in these scenarios, even though it feels like I'm 'over communicating'
The other things listed out in the article feel like tactics that can help here, but for me 'don't assume everyone has the same information you have' is a really helpful mindset to hold.
(I think that the article sums that concept up well)
if it feels like "fluff" it is fluff imo. And that's something that most incompetent PMs suffer from.