Somewhat inevitably, GP3 will follow the lead set by GP2 in adding F1-style proximity-based DRS to its cars in 2017.
We introduced a new car in GP3 this year and it has given us 100% satisfaction in terms of reliability so we decided to add another layer to the drivers’ apprenticeship with the addition of DRS in order to prepare them for GP2. Of course, it will also spice up the GP3 races which have been a little bit too quiet at the beginning of the season, but they have started to become extremely enjoyable in recent rounds. DRS will also attract drivers to the series because they are always looking for anything that will help them prepare for the future.
http://theinsider.gp2series.com/gp3/issue104-gp3feature/newsflash-push-my-buttons/
Unlike GP2, which had reliably great racing before GP2 was introduced, GP3 had tended to be more processional. But I’ve seen more than enough tedious DRS motorway passes never to want to see one again.
As a result of the rules change GP3 will also relax the restrictions on car set-up. The restrictions on what wing angles the teams could use will no longer apply from next year, allowing them to run higher downforce levels.