Thanks @SausyFC for clarifying the chat box issue, but I'm interested to know why it's been changed.
It seems odd that we can no longer chat to friends during normal games. In many cases they may also be watching the games and it's fun to comment on what's happening in the match.
I'd be interested to hear the logic behind removing this from the game. As far as I can tell, a fun feature has been removed for no purpose.