Often these are the product managers building follow-on features that don't get the usage they want. Users aren't using them, but monthly usage is the currency of so much PM work that they have to try to draw attention to it.
Some people don't know how to operate a TV remote controller, unless it has 1 or 2 buttons.
It's protection against the frustration that a few experience: ultimately unable to use a thing or jam it. At the expense of the majority bugged by mild distraction.
Raising the visibility of something, or pointing an arrow at it is fine, but don't dim and block the rest of the UI immediately because I might need it for context to understand what the hell you want me to click next and why. If I can't do that, then it's just a forced speedrun of 20 steps that I will immediately forget.
It feels like many of these forgot that the point is to teach for the future, not to boost extremely short term interaction metrics. Showing (much less a single time) is not usually enough to teach, you need to establish context so they understand why instead of just what, and generally offer repetition.
It feels like vendors just tack on the first thing that pops into their head. How do we tell users about the new feature? Pop-up dialog! That should work.