What would happen is that your name & CV will be flagged to the industry as a NONCOMPLIANT. Word of mouth is a very powerful tool!
Really, if any pilots believe that they should accept unfair and illegal contracts because they could get "blacklisted" by some silly little man behind a desk who thinks his word of mouth overrides an airlines need for a decent qualified pilot then more fool them, and if that
IS the way in which a certain airlines conducts its recruitment then better off not working there anyway.
Believe it or not, there are still plenty of good establishments out there who are more interested in employing decent skilled pilots and not some second-rate brown-noser recommended from the old boy's network.