What's with the accounts named Montest and ROBOT?

Currently loading into a game on PBE. Two players on the enemy team are called MontestXX and three are called ROBOTXXX with the X's replaced with numbers. One player on my team is called MontestX. Is this a result of new players being added to PBE? Or is this a sign of something more malicious? Will post screenshot of results screen after game. EDIT: The entire enemy team afked on their fountain near the end of the game. The Leblanc was responding in All-chat, but the Garen/Malphite bottom didn't even attempt to CS properly and used Summoner spells for little to no reason. Screenshot has been attached of results screen.
Report as:
Offensive Spam Harassment Incorrect Board