There are also lights around the track everywhere, I think it's for the next patch, involving lighting. Those lights in the pitlane are less difficult to make than the lights around the track, but maybe that's something to think about untill the next patch... or untill a dev says what it's for (prolly not)
But you still can't jump the start. What is the point of delayed lights when someone can just hold there pedal down to the floor and take off as soon as the light changes anyway?
Because the more connections there are and people in the garage changing setup or in spectate, the longer it takes for those people to get put on the grid. There has been countless times I've missed the grid and had to start from the pits or been put on the grid just as the green lights go causing meyham since I wasn't ready for the green.
It seems a little long when there are few connections, but quite helpful I believe when it's a full server.