Whenever you are flipped upside-down while traveling upward in midair, vertical deceleration is slowed. Being at any sort of angle while midair can cause minor movement toward wherever the bottom of the vehicle is facing (depending on the context it may or may not be noticeable). However, there are multiple ways that it could be implemented into tracks, and it is a very minor affect. So, If it were kept rather than being fixed, there would be no difference with quality of gameplay, and track-makers could be more creative.
One other possible option would be to fix it but have a track piece that can enable it (with a more increased effect) and a track piece that can disable it, which would be a pretty unique feature in my opinion.