Proposal: Operations Research
Does the private beta start instantly when the commitment percentage reaches 100%, or a CM needs to take action?
The latter one. The site does not automatically get created at 02:45 on Saturday morning if that's when 100% is reached. Rather, a notice appears saying that this proposal reached 100% commitment and that the team is preparing for its launch.
New sites usually launch on a Tuesday during U.S. business hours.