I think it's a good idea, as is having a 300m straight. Corners into a sprint finish are just bad news, mainly for the following bunch. It's just a lot of risk for the peloton.
Sprint lanes seem like an interesting concept, because it would have a clean line, but once you get into it, you're committed until someone completely overtakes you. Kind of like the F1 rule about allowing one blocking move, but not two.
It also keeps the outside lanes cleaner, which is where the biggest risks are.
The only problem is that it may result in some bad crashes. Imagine three riders in a line, 3rd rider ducks into the lane, then the second rider also ducks into the lane, sweeping the front wheel.