I don't think that this is a practical solution.
Lasers are very focused and don't spread out like normal lights, if they were to spread out the power requirements would be huge.
Also It would be walking a very fine line between delivering enough light to be noticed and too little to cause eye damage to people looking up.
Lastly You would have to check the wording on the agreements banning weapons in space, even though it is not the intention this could be viewed as one.
While this is an interesting idea I don't think it is very practical and there could be better solutions.