The buff was amazing but i don't think it made Dynamo top tier, it's just no longer a joke weapon. I'd call Dynamo viable the same way that Glooga Dualies are viable.
From my experience playing as and against Dynamo since the latest patch I've still had multiple experiences where the horizontal flick did 0 damage at nearly point-blank range so... yeah. The extra damage is great, but once you get used to the new oneshot range, you're still able to kite enemy Dynamos and dive on them right after you survive the first flick, especially if you're playing a weapon with a bomb. It's vertical flick is still hot garbage, it still loses hard to any weapon that outranges its oneshot, and it's still countered or outclassed by every top pick and a solid 80% of everything else.
Right now I don't really see how either of it's kits fit into the meta. vDynamo is outclassed by literally every other cooler option and gDynamo suffers from the opportunity cost of running a Splat Bomb paired with an ink hungry main AND Super Chumps. But the weapons you pick in SoloQ don't really matter too much compared to competitive (and I've had a lot of success with Dynamo in ranked too) so it's definitely good enough now for the average player. There's even a Dynamo with 3000xp right now on the X rankings.