I've been eating in that neighborhood for years now and there aren't a lot of places that have disappeared, though a couple have relocated. One on the north side of street near the El tracks burned down a few years ago (can't remember the name).

Ba Le still serves up amazing sandwiches from a new (in the last ~2 years) spot one door south of their original space. They've also expanded the menu. I was there on Saturday.

Sun Wah has moved to a much larger space on the east side of Broadway a couple doors north of Argyle.

Nha Hang on Argyle (north side, a couple blocks east of Broadway) has experienced a surge in popularity in the last year or two.

Chinatown favorite Lao Sze Chuan has opened an outpost on Broadway down toward Lawrence.