Nobody knows what will happen to the MRJ. Mitsubishi's crowning achievement was the 1999 mitsubishi eclipse. Right now, the MRJ 90's getting certified without the wings falling off sometime this decade seems like a dubious prospect.

TSH has the option of turning their order into 70s. (I've also heard the same about turning E2's into 175 orders) So that's a backup plan to the scope issue. Also, they can sell or lease the aircraft or sell the delivery slots to mainline. And while I would hope relaxing scope wouldn't happen in this climate, money is king, and the major airline pilots wouldn't hesitate to sell us farther down the river for the right price.