Well this isn't true.
Charlton is known for big leaguing other promotions on comms. He does it to NOAH, AJPW and Dragongate all the time.
Charlton has been taking crazy digs at AEW the entire year. This was just his magnum opus. He flew way too close to the sun.
Again, he did it all whilst Rocky Romero (an AEW & NJPW VP) was on the desk. Rocky and Walker tried to reign him in. NJPW has historically taken their partnerships VERY seriously so that level of disrespect on comms from one of their office employees to a business partner without clearing it first was always going to end this way.
He was just extremely unprofessional.