Dragging a ghost path from a "Ride with scenery" onto a path with more path above it will delete the pathing above it when you drag the ghost path off of the "merged" lower path. You do not get money refunded to you for the deleted path.
More specifically, dragging the ghost path from this powered launch looping coaster onto the concrete path below
results in this:
I'm on Windows 10, V0.4.9, and I made sure there were no plugins in game.