It's been some time since I've dealt with TWL COD4 match configs however, I believe the personal greetings and ban announcements are to be disabled while the server has the TWL configs enable for match mode. When setting up the server for a match the league config may disable announcements. When the match is over you need to run the commands which will set your server back to public mode (if that is what you want).
Again, it's been some time since I've used the TWL configs so things may have changed.