It's not the old scoring criteria from ten years ago or whatever, it's literally the post-reform stuff that was in vogue as of 2019. The newest set of Unified Rules came out in 2022. Here's the exact wording:
To me, the bolded section is clearly acting as a qualifier for the "successful execution of takedowns" bit by stating that a fighter isn't credited with Effective Grappling until he/she does something with the takedown, whether that's landing GnP or attempting a submission. I would assume advancing position with neither of the other two would also be an allowable form of "launched attack" to validate said takedown, but would get you a comparatively low amount of credit. That said, I have always thought that this clause doesn't really apply to high-amplitude takedowns and slams, because you are quite literally "establishing the attack" with the takedown itself. Even if you aren't able to follow up on a massive slam with GnP or a submission attempt or a great position, it should count because we have years and lots of finishes to establish that those types of techniques meet the standard for "Impact".
Now, with the 2022 edition of the Rules, they really pared it down to where it just says this:
No more qualifier. Was that a deliberate exclusion on their part in an attempt to make all takedowns count at some level as Effective Grappling? Or is the spirit of the previous edition still alive and well do they feel that the "...and impactful/effective results" bit sufficiently sums up that you shouldn't really be scoring empty takedowns that the guy on top does nothing with all that highly? Of course things get even murkier if you read too much into the sections of Impact and Dominance (which are no longer locked away under the 10-8 banner) and imply that body language is scoreable and maintaining a high pace of aggressive positional changes alone can display Dominance on one fighter's behalf... but that's getting too far into the weeds and in my mind applies mostly to 10-8 or 10-7 rounds.
Personally, I rate high-amplitude takedowns, GnP, submission attempts, and positional improvements (whether on top or as a result of a reversal) as Effective Grappling. Obviously they all exist on a sliding scale and are evaluated on a case-by-case basis, so no real order of hierarchy there. Takedowns that don't land the top guy in a good position and where he/she doesn't follow up are much like empty clinch control: it's just Fighting Area Control in most cases -- though some exceptions may apply, I suppose.