So call it Self-Supported Bicycle Touring then ... that might be easier to understand.

Support will not be provided to the cyclists, like it is for some tours, but you can find your own "support" (i.e. buy dinner at a shop) along the way if you want to.

Fully Loaded Bike Touring implies that cyclists will indeed need to bring absolutely everything they might need because there is no "support" to be had anywhere of any kind for the duration of the tour. These days, for most cycletourists, that sort of situation is rare.