There are projects without announcements of the team, which successfully start their work and conduct ICO. But if you think about it, why hide your identity? I also consider many projects as a scam if they don't have technical support in the telegram and their own group
I have the experience of participating in a project without a team, in the end it becomes a waste. However, the team becomes very important in the project, without a team, the project will be difficult to develop.