But doing it all at once and having it opt-out accomplishes that. If "John Smith" has a public TripleByte profile next week, as a third party the only signal I can get out of that is that "John Smith" passed the TripleByte interview some time in the past. I'd be okay with this if TripleByte gave a couple weeks to opt-out and made certain potentially sensitive information opt-in. Just make it 4 weeks to opt-out and by default don't display the date they interviewed with TripleByte and don't display "Open to new opportunities". Then just ask the user what they want after new interviews and accepted job offers.
If they made the initial launch opt-in then that signals that the user deliberately chose to advertise that to the world. The message a current employer gets out of something that's opt-in instead of opt-out is notably different. This is just like the whole opt-out fiasco with the Do Not Track header. If it's opt-out, the signal is largely meaningless. In this case that's a benefit.