The short answer is that while the basic concept of steering on the guide rail remains the same, the driving experience shifts because of the fundamental difference between internal combustion and electric drivetrains. You won't feel the same way a gasoline engine did because the power delivery is completely different. ICE engines have a lag between the throttle input and the resulting torque because they have to spin pistons. Electric motors, conversely, provide instant torque right from zero RPM. This usually translates to a very quick, punchy acceleration off the line that feels immediately responsive, even if the overall top speed limit on the track is identical to the old cars.
Regarding the handling and the bumpy sections, you might notice a subtle change in the ride quality. Because the battery and motor are usually located in the chassis area, EVs have a much lower center of gravity than a comparable gas vehicle. That means when you hit a bump in the track, the vehicle's mass distribution is more stable. It might handle the side-to-side jolts of the guide rail differently than the heavier, older combustion cars did. However, the guide rail itself is what dictates the path, so the steering input will still follow the prescribed geometry; the feeling is just slightly modified by the physics of the electric setup.
I understand the concern about sanding off the intangible feeling, especially since those old engine sounds and exhaust fumes were definitely part of the nostalgia. The whole shift is really about making it more modern and cleaner, which is a huge step for the park itself, given the environment. If you're looking for the 'real driving' feeling, the EV will give you immediate response, but it won't replicate the weight and sound profile of the classic gas ride. Just manage expectations that it's going to feel more smooth and immediate rather than something that roars to life.
It sounds like a fun surprise for your daughter. The technological jump is big, but for a kid on a short ride, the immediate acceleration will likely feel exciting and snappy, regardless of the specific transition details.