It certainly does look like the tip of forklift blade, IF forklift entered from the drivers side and blade didn't reach all the way across. OP said
"When I went to pick it up, the passenger side dually bracket was not extended (the truck that brought it to Yakima was a single RW), so a forklift picked up that side to allow the bracket to be swung out."
Sounds like forklift entered from passenger side, assuming flat blades would be hard to punch like that unless blade was only inserted under camper a few inches with a pretty good tilt or a block on blade? If the forklift reached in from the drivers side, regardless of how it should have been lifted as related, doesn't mean thats how it was lifted-Wasn't there so just conjecture from here. just awfully coincidental either case.
Unless you have bottom replaced or repaired Id try to seal/glue the crack prior to surface sealing. Getting a quote would be a start. Unless theres a load directly above I also don't see as structural. Looks like fiberboard?