To be able to control HomeKit devices remotely it’s necessary to pair them with a hub (i.e. Apple TV, HomePod or iPad).
With the HomeKit Controller HA integration, is it still necessary to have one of these devices or does the HomeKit Controller integration allow the HA instance to function as a HomeKit hub as well?
The HomeKit Controller would act as a HomeKit hub, in a way that for example your homekit light bulb would talk directly to HA, and not to any Apple hardware.
So this statement is true:
HomeKit Controller integration allow the HA instance to function as a HomeKit hub