The dates for CM previews went out a few minutes ago. I’m trying to get them confirmed.
So far the schedule I have is this:
May 4-6: Media Previews
May 7: Golden Oak/Club 33
May 8: The first potential date for DVC/AP previews
As far as boarding groups go, I’ve been tracking the ride’s downtime. It looks like formal testing started around the middle of March. It’s averaging an hour of downtime per day since then.
That might sound like a lot, but for perspective, here’s what other EPCOT attractions are averaging in downtime per day over the last few weeks:
Frozen Ever After: 75 minutes
Remy: 75 minutes
Test Track: 114 minutes
Still, I’d expect GOTG to open with boarding groups for a couple of weeks.