Why though? They get free advertising and by banning him they showed everyone else that they will follow through on banning if they share information so it stays contained.
Honestly, I think Valve is just kind of doing a soft release/announcement and are trying to build up hype slowly like this. If they were really worried about leaks they wouldn’t have given anybody in it unlimited free invites to send to anyone.
It wouldn’t surprise me if this was a way to avoid typical launch day server issues either.
Rather than have everyone dumped into their servers as once, they let things ramp up.
Though that could be giving too much credit considering it’s in alpha. Aloha would suggest its still far from release, probably too early to bother stress test the servers or w/e.