Im not exactly sure where they THINK they are going to be flying these aircraft, or for whom, but they clearly see a niche that NEITHER Boeing nor Airbus intend to fill (90-120/150 seats).
As for the union banter, I will leave it to others, save to say that what TSA management did with TSA pilots and GoJet blows. ALPA, warts and all, is STILL THE VOICE of aviation safety and security in GLOBAL aviation, but will have to tread carefully as some of the largest contributors appear to have an increasingly smaller and smaller say in the day to day operations and direction of the Association. Therein lies a SIGNIFICANT problem, because if ALPA becomes THE REGIONAL Association, then their coffers will be a fraction of where it is today, which is already seen as "distressed."
With DAL/NWA being such a major contributor, ANY thought of them leaving due to regionals collective dominance would be devastating. Add a UAL/CAL combination and any thoughts of them leaving and the Association folds in on itself. Conversely, ADD AMR and throw USAPA back in the mix (unlikely considering their stated goals of staying SEPARATE from the Cactus pilots and NEVER agreeing to a merged contract) and you have an entire universe of independent operators and very little cohesion of purpose or assets. Food for thought.