Nope. Horsepower is torque/time.
Torque is more important for acceleration than horsepower. It's all about the force that wheel contacts the road, and must be greater than resistance to motion. Resistance to motion is the total of all of the friction, rolling resistance, and air resistance that is exerted on the motorcycle, and these values of resistance change as the speed of his motorcycle changes. When force generated at the tire contact point is greater than the total resistance of his motorcycle, the motorcycle will accelerate. The greater difference between tire force and resistance, the greater the acceleration.
When you increase force you increase acceleration. Wheels connect to axle, which connect to final drive, which connect to motor, so force at the contact point (tire to road) is the torque generated by the axle (force x distance = torque). As a result, when you increase the torque at the drive axle, you accelerate more quickly.