Jeff Kaplan the game director of Overwatch has hinted that changes to Sombra will be implemented in the future to make her less powerful at the highest levels of play.
For those of you who don't follow Overwatch League and just play Sombra in Ranked, you're probably incredibly confused right now. After all, Sombra is very difficult to play effectively in Ranked because her kit relies so heavily on team work. However, in Overwatch League, where a team can support you and play around you is guaranteed, Sombra is incredibly powerful.
Kaplan stated in an interview with The Loadout, "Even among Master and Grandmaster Overwatch players, Sombra doesn't perform very well because she's so completely and utterly team dependent. But once you get these mastermind Overwatch League coaches showing their players where and when to EMP, she works."
This suggests that in her next revision, Sombra will likely receive changes to make her more self-sufficient but the features that make her so powerful when backed up by a good team will be toned down. this will hopefully allow her to become more viable for non-competitive players when they're forced to play with strangers, and less dominant for the competitive scene.