Well Fuma was competing with Raiton as the single target filler skill, not Bhava. Raiton also got buffed by 40 potency, but didn't lose Dripping Blades or the slashing debuff (they didn't apply to magic ninjutsu.) Currently Fuma is doing 316.8 potency (after slashing debuff and dripping blades) compared to 360 from Raiton. 33 potency for one more mudra is... meh. In Shadowbringers it's going to be 140 more potency for one more mudra, which is absolutely worth it.
Granted, potencies can change pretty easily but unless Fuma sees a significant buff it's likely that you'll only see it during TCJ, even if one's internet connection isn't the best.