It is truely just a slightly educated guess, based on that guy that managed to do it. Maybe he was wrong.
If you read the manual about the BRIGHT switch, you could interpret there is more going on that the bright cap alone (or not?):
If so, what is the difference besides the bright cap, we could wonder...
If not, I'd guess the NORMAL option is without bright cap engaged.
"Many amplifiers contain a “treble peaker” on the volume control. On some amps this switch is included as a pull switch on the volume control or toggle switch. On others, the circuit is hard-wired. Every amp TYPE on the Axe-Fx II includes a bright circuit. If the original amp has no bright circuit, the default state is off, but BRIGHT can be turned on to apply circuit values most suited to an amp of that general type. If the amp has a hard-wired treble peaker, the default BRIGHT state is on. The effect may be subtle or quite pronounced, depending on the amp selected, and is also affected by the BRIGHT CAP setting."