There's also Skype chat group if you don't like Discord. :)
I think if you really want to play Crysis multiplayer, you will always be able to find the way, just don't be so damn lazy. :D If you don't want to do that, it means that you don't want to play Crysis multiplayer and inviting anyone like that to the Discord or Skype group doesn't help in any way. Both groups already contain quite a lot of people that nobody has ever seen in the game.
By the way, i've never heard about that Kik before. Maybe it's good but it seems that Kik Messenger works only on modern Android and iOS phones, and web version doesn't exist probably, so i can't even try it... :(