While it would be nice if Frontier could add this to the game (and add Cassiopeia A while they're at it) there are limits to just how much Frontier should do to tweak the galaxy to include every major discovery that enters the news headlines. Trappist-1 should be located near x=-20.113341 y=-32.575633 z=7.435164. I'm sorry to say that it just doesn't exist in the Elite: Dangerous universe. Frontier did a good job of including many of the major visible objects in the galaxy. Including every single one of them would have been quite the task.