im 905% sure that Sombra won;t return since it just seem like the toy description is a result of someone doing a lazy copy and paste job, but if he is coming back, i have mixed feelings about it.
mainly becuase like i mentioned before, i'd rather the g4 characters stay dead and only appear if it was like flashbacks or something. It'd feel like more like they;d be relying too much on G4 to bing people in rather then be it;s own thing, if that makes sense.