Air carrier Dispatcher reported the flight crew sent an ACARS message that the Hazmat cargo was not loaded as planned at departure. Dispatcher eventually provided the flight crew the updated documents during enroute.

Narrative

Flight crew sent ACARS message as they blocked out; stating 'XXXXX IS IN BIN BD. NOT BL.'. It was later determined article had been placed in a different subset of one of the cargo bins; due to the size of the pallet. Assuming this was related to dangerous goods (crew likely meant Dangerous Goods Form); dispatch called Load Planning to see if they had information regarding the load plan. Load planner stated they did not do anything with dangerous goods. Dispatch then called ZZZZ Hub for more information. It was mistakenly believed Company cargo ops went home at XA:00 (that time was actually XB:00). ZZZZ ops said the person responsible for cargo information did not arrive for another hour; but were otherwise not able to assist. They did offer to call Load Planning and discuss with them. The chief dispatcher was notified. He was eventually able to get with Company cargo; who sent updated paperwork to captain via company email while the flight was enroute. He said a reportable violation had taken place due to flight departing with incorrect paperwork. Crew chief in ZZZ had modified load without any sort of communication to dispatch; minus flight crew sending message saying change had taken place.Cargo operations should not have hours of availability. Those involved in the cargo process should have access to pertinent information regarding cargo operations; and dispatch needs to be able to access that information in a quick; accurate fashion. Cargo operations at a major; global airline should be open 24/7; 365. It should also be located in the operations center. Load Planning should have more information regarding dangerous good placement within the aircraft; as that does pertain to the loadout of the aircraft.