Usually passengers with ship tours go first. But I think if you're a suite or a lot of stars, that may be different. As a 4 star, I don't remember being told to report to a different place. We don't take tenders often anymore. I think passengers get the tender tickets at the passenger desk, then they announce them. At some point, they announce no tender tickets needed.
Having gone on mostly ship tours, sometimes we've had a long wait. This is all ports, not just Bar Harbor.
When we were in Greenland, the captain cancelled all tender rides. That's after several tenders had gone out. He managed to get them back. He put extra crew on the boat to spot the icebergs.
Oops, I thought I was in the Canada/New England/Iceland thread. Sorry.