Probably. I've been offloaded before and shown up at gate and politely insisted I be put back on. "I'm here, on time, and have a valid boarding pass" is much harder to argue with in person than it is to say no to another staff member over the phone. If they had already given your seats to someone else and the flight was full then that's a diff situation ofc.

Sounds like either the flight was overbooked and they couldn't put you back on or the gate agents were lazy and couldn't be bothered. But yeah going to gate and politely making your case would give you a better chance.

That said if your bags had already been re-routed, not sure that can be undone easily?