I can confirm that the intention of that prior sentence is to provide this context.
The rules verbiage was updated back in June 2016 after it was unclear whether the points should stand or not for any of this activity (thread is here - Ruling - Playing out of turn - #7 by dbs).
In the private correspondence between IFPA and PAPA about this update, MHS added that sentence to the verbiage. Here were his comments to Zach and myself about it:
“My opinion is if all players are paying attention to a multiplayer match, this issue will never come up. Making the points count is not only clean, but it keeps people around the game in question and focused on what they’re doing, which is always good.”