Symettra is a hero that was very underwhelming. Symmetra however was overtly situational. Her abilities were very good only on the defense but on offense, she was basically considered worthless.
Symmetra will be the first character in Overwatch to be having two ultimaetes. In addition to her teleporter, she will also have a new Shield Generator. Shield Generator will keep generating shield in a large AOE. It will help make Symmetra viable in competitive gaming.
Her Barrier skill will be reworked and be made into a Photon Barrier. Photon Barrier will be making a big photon barrier in a line and will help protect the team and the players. It will also be used aggressively.