I am not sure why employees would be motivated by option grants unless they knew how much they were worth relative to the company. Unless the company "appeared" to be doing well. Even then, the company could issue any number of shares and dilute the employees' ownership possibilities. I feel like a minimum of level 2 info (as shown in the chart) would provide the employees a good enough sense of what is going on, and therefore be more motivating.
Does anyone have any data that shows how forfeiture rates are affected by levels of knowledge?