I have been in a situation where a flight was delayed, multiple revised departure times were posted, and they ended up scrambling to get people aboard so they could depart significantly earlier than the latest posted time. They ended up leaving people behind who had left the gate expecting the later time. Admittedly this was a number of years ago, but if it was me, based on my years of experience I wouldn't trust them as far as I can spit. "We're not happy until you're not happy."