Correct me if wrong, but cannot the same 20 years be “thrown away” by a pink slip because someone doesn’t like you or the way you act, smell, etc without some sort of protection?
With the recent picture of several Instructors flipping the bird, an unsat on a checkride because they don’t like you or feel you supported the union, is a very real possibility. Without a union, the training review board will return, then the company will decide you are no longer retrainable and subsequently fire you. At that point your 20 year career at Flexjet is over with no recourse to save your job. Get your resume up to date.