Very unfortunate situation and the exact reason that, when I travel with pets, I schedule layovers that aren't likely to be missed in the event of issues.

Unfortunately on a flight like ATL-HNL where there is single daily service, a misconnect generally means a 1+ day delay unless you are rerouted.

Your concern about the dogs being dealt with as cargo shouldn't be one. Cargo is very often treated better than bags & passengers when it comes to priority for a flight. People are offloaded before the cargo.