Most of the reports are that you still usually get a ride in after the EMM crowd but before the RD crowd arrives. The EMM crowd will be heading out of Fantasyland for the most part so they aren't going to make it any more crowded. It does mean you won't get two rides on 7DMT before the RD crowd arrives but our experience (and others who've posted recently) has been that you don't necessarily get more then 1 ride on a non EMM day. You are also pretty much guaranteed that the park won't open earlier and make your PPO useless.
All that said, a lot of things can happen (ride can go down, open late, etc) and you aren't guaranteed a ride on 7MDT. If that's very important to you, I would grab an FP also. You can always change your FP to something else once you've ridden.