It is not true. Which is why I advised the controller automation simply sends Escape to all emulators.
There is no default exit hook/hotkey for the actual emulator settings when it comes to the controller and keyboard bindings.
If someone mentioned that it is likely referring to those defaults in the Pause Theme tabs. Those are needed for when you are in the Pause screen Launchbox will use the emulators bindings for things like Save, Load, and for Exit. To be clear it is only using the emulators Exit hook to Exit from within the Pause screen and if there is a script needed for that it is placed in the Exit AHK Tab. That tab is specifically used for Exiting from within the Pause screen. Not to be confused with how it exits during gameplay.