So many people have been making the argument for in-game names instead of GT so ill just leave this here.
So the reason to keep GT over in-game name is this.....
The only reliable way we have to talk to each other is xbone party or send xbone messages. If you use in-game names instead of GT for characters then we will have even less of a way to communicate to people. Making this change before the release of text chat would only further cripple this games grouping ability. I send dozens of xbone messages everyday to form dungeon runs, sad that I have to resort to that but I'm left little other choice.