My first thought was that this measure is going to have little effect on attracting new highly skilled workers to Japan. Highly skilled workers will tend to be employed by companies who will be willing to do all the paperwork to ensure that they can work in Japan. I would imagine that other factors such as pay, conditions, career opportunities, perceptions of Japan, and family circumstances would be much more important than whether you can become a permanent resident after 5 instead of 10 years.