The sauce mixture not only adds flavor to the meat during cooking, but also doubles as a vinaigrette for the noodles.
Bring 4 quarts water to boil in large pot. Off heat, add noodles and let sit until tender, about 5 minutes. Drain and rinse under cold water; set aside. Whisk soy sauce, 2 tablespoons oil, ginger, and garlic together in large bowl. Combine cucumber and vinegar in second bowl.
Heat remaining 1 tablespoon oil in 12-inch nonstick skillet over medium-high heat until shimmering. Add pork and cook, breaking up meat with wooden spoon, until browned, about 7 minutes. Stir in scallions and 2 tablespoons soy sauce mixture and cook until scallions have softened, about 2 minutes.
Add noodles to remaining soy sauce mixture and toss to combine. Divide noodles evenly among 4 bowls and top with pork, cucumber, and cilantro.
For best results, make sure to shake off all excess water from the noodles after rinsing them.