Testing with guests is literally just they will open the queue line up and let guests line up. That's pretty much it. After a few hours it will close and then be done for the day. It's not advertised in any way.
I don't recall members being promised to ride it before it opened to the public. Just that they would have members only ride time.
On another note BGW has always had a large amount of passholders. The number has increased recently but they have always had a significant number.
Thanks for the clarification. So I guess the best bet is to keep a hawk-eye on it throughout the day and also check the forum (assuming if someone from the forum notices the queue open, they will post here)
And right. No promise of riding it before the public opening. I believe the wording used was "early ride times to be 'among the first' to ride it". Similar wording was used for cutback.
I still wouldn't be surprised if someday they decided to do something like "ERT slot for only platinum" or some such.