Chats in gambling is a good idea and a way to build relationships with fellow players.
As long as there are no signs of cheating say on a poker site, then I think this is a advantage to the players.
Those people who are used to play gambling at physical sites, they might feel bore playing gambling all alone. This feature of chat in the online gambling help to reduce some sort of loneliness as they can now chat with other people while playing gambling.
The feeling might not be the same as talking physically to a person, but still something is better than nothing.