That's not a gimmick. After B3, people are conditioned to block high afterwards so gun hits. You get some respectable meter and chip damage with this.
It's also -1 on block instead of -3 so you're at a reduced disadvantage on block. Certainly useful if mixed up well enough with his other options.
True, it's all about conditioning your opponent. If you're using mostly overhead at the end, odds are they'll always block high, unless you're using a good amount of back 3 baton sweep(in which case this is less advised since you're conditioning your opponent to block low more than they would otherwise). I don't really use this a ton, it's something to be used in controlled bursts I feel.