The idea of having text chat in game has been tossed around quite a bit. Usually one of the main issues brought up is that it could harm immersion. Be it with chat bubbles appearing on screen as people are talking, or just text appearing on screen.
An idea i heard that i think may solve this problem would be to have a tablet in game. Similar to the camera. something that we can put away, and just pull out to see/send messages sent by text. People who send a message over text can just have an icon over their head if they said something, and if they are trying to contact someone specifically, you could have a small message icon on your HUD to check the text tablet.
This would resolve the fear of cluttered text messages filling our view in game.
There is always the argument that typing in VR is a pain. But I think those who would like a text chat would appreciate this, even with the slow typing method of virtual keyboards