Maybe, maybe not. There is a thread on this in the Galaxy Edge subforum. First boarding group distribution occurs at 10am, second at at 1pm, and (possibly, depending how quickly the line is getting through boarding groups) there will be a third boarding group at 4pm. Regardless of when you show up, boarding groups are not guaranteed and have been fully distributed in under a minute. Obviously, arriving and trying for the 10am boarding group gives you the best chances since you get three tries to get a boarding group instead of, say, arriving at 2pm when you only have one chance, and it's possible few or none will be distributed in the 4pm batch because the ride is running behind for the day.
Just use MDE after entering the park.
Read the first post of this thread then you can read recent reports in the newer posts
I am starting to think arriving in time for the 1:00 boarding group distribution is the way to go. Someone wrote that everything else is a walk-on but I'm not seeing that for HS. It sounds like lines diminish as the day goes on but all of the headliners are over an hour at rope drop. It also looks like the hardest time of the day to maintain a safe distance. I know I'm sacrificing a lot of my chance to ride RotR by skipping the first distribution, but my day is over once the kids have had their limit of standing in long queues in the sun.
It just opened and the only thing with a line longer than 20 minutes is MMRR, which does go down as the day goes on. I'd go ride TT and RnR, head to TSL, rides the other GE rides, and then hit up MMRR in the afternoon after a nice lunch....then ride everything again (that's my plan anyway. I've yet to see anything in the last few days that gets over an hour beside MMRR, so I think you'll be fine if you really wanted to get there at 10 for a BG. I've already booked a late lunch to take advantage of AC & a mask break so I can refuel for the afternoon when it starts to clear out.
