I wouldn't have a problem with a cba rule limiting agents from commenting publicly on players not signed by that agent or commenting publicly on any team that doesn't have a player represented by the agent. Also, any comments about teams would need to be in the context of the player on that team.
For instance, Rich Paul would then be breaking cba rules by commenting about NY or Boston or LA when it comes to Davis. Paul could comment about Boston in the context of Marcus Morris or he could comment about the Lakers with anything having to do with Lebron, but could not comment about LA and Boston or NY about Davis.
Not sure what you can do about agents feeding false or misleading stories to their press contacts to drive a public narrative, but maybe my suggestion would help.