Yep. That's a strong possibility. Dude didn't take any water, which is a good sign that he has a soft landing coordinated. He's either going to end up at the cantina camp, or this is a premeditated "tap with fake honor" situation. Not slighting EJ at all, I just think he is past his prime.
One thing working against the group merge theory is that I believe the cantina camp is in the opposite direction from extraction, assuming they have the same extraction point as Trish and Jen. I think EJ implied he was going to look for greener pastures closer to extraction, so if he ends up at the other camp, then the producers have been more sloppy than usual at hiding the shenanigans.
Amber wasn't planning THAT far ahead. It was intended to serve a dual purpose, as a dock for fishing the main canal, then later a raft for extraction. I wish Amber had taken it with her, but it would not have fit the narrative that we are being fed.
I agree with the planted cayman theory. Typical "need protein for extraction, oh there's some" bs.