First, I understand your needs of wanting more updates to the efforts to stop disruptive play, and the good news is that it is coming. Andy B recently mentioned…
Now I will note (and this is my own opinion), that in many cases I don’t see saying “EZ” to fall in the category of disruptive communication unless there is specific context to show they are fully intending to directly abuse specific players. Even then, I think a little salt helps lighten the mood in many situations and that is why match chat does exist. In my opinion, the most disruptive communication comes from team-only channels (team text chat and team voice chat) because players, unfortunately, like to blame others when they see their teammates perform to a certain perception of their own standards.
As far as Endorsements goes, the development team has mentioned that they knew introducing the system would be the first step to help reduce disruptive behavior, and that first step did have a strong initial impact. Of course, the system is not as meaningful today as a good portion of the community, including myself, have continued to have little concern for our endorsement ratings. Thankfully this is why they have confirmed improvements to the Endorsement rating system will be coming soon.