I'm not sure if this is true or not, but nobody verified the authenticity for or against...
Basically, Riot Employees. Some might not have seen the email yet, because, like they auto filter company crap to some folder and check it later, because people were abusing the mass employee announcements, with like help the children charity crap last month, and a lot of people got tired of them, but basically, top level brass is coming down hard on folks at Riot who post unapproved responses on the boards. All red posts have to go through HR for now prior to posting for approval.