The Hue wall switch dongle creates a "fake" switch, the bulb is powered 100% of the time, the on/off on the wall switch just tells the hub to tell the bulb to s

The Hue wall switch dongle creates a "fake" switch, the bulb is powered 100% of the time, the on/off on the wall switch just tells the hub to tell the bulb to switch on/off. You'll find that the failure mode is the opposite of what you're worried about. If you rip out your hub and flip your main fuse off/on you'll find yourself in the blinding light, not the dark. When the bulbs are powered on and can't reach the hub they default to 100%.