I wouldn't dispute any of HH's 5 truisms , though I disagree with his conclusion.
Having said that, 3 of the 5 points he made are irrelevant - relating to restarting production of an upgraded old design - which clearly isn't what Saab are contemplating.
Yes, developing a new design is horrendously expensive, no argument with that statement. However the fact that Bombardier and ATR are struggling to make a profit competing with each other (with two products, neither of which can be stretched much further) doesn't necessarily mean that an all-new 90-110 seat Saab with the new GE engine wouldn't do well in competition with jets in the under 400nm market.