If there's no EMH in the Studios, I'd be queuing up at the gate around 9am, perhaps slightly before. We were there last week and got into line at the turnstiles at about 8:55 (we had booked a Covid test at the Village at 8:40, so went through the security queue in advance for that, and got out of the testing centre a lot quicker than we'd expected) and there were already at least 50-60 people waiting - admittedly they were all split between about 10 different lines, so we were still very near the front regardless of which one we'd picked. Over the next ten minutes, the queues then did start to build behind us to a reasonable level.
The turnstiles were then opened at about 9:15 and you could proceed straight through Studio 1 to your first ride. I walked fast to Crush (did not run, but a few others did and overtook me) and I got to the entrance to the ride about 20th in line. We were then held there until 9:30 - only once the announcement had played over the speakers that the park was open did we get let into the queue itself, which takes at least 5 minutes to walk through the entirety of. Looking back behind me as we were let in there were easily a few hundred people waiting in the queue that snaked back all the way to Studio 1 - so if you're thinking that the park is only going to open at 9:30 exactly, this is how far back you might end up being.
I was probably in about the 7th or 8th ride vehicle to depart and by the time I was off (9:40-ish), the line was almost (but not quite) contained within the switchbacks of the queuing system but the sign did say it was a 60 minute wait already.
