This is one of those cases where having a 'confidential' S-1 is weird for me. Prior to opening day they have to have a 'public' S-1 so what is the big deal? Actual numbers on paper leading to a buzz kill ? I don't know. But as an investor I treat it as a negative.
I wonder if it's to avoid people seeing a sharp drop in revenue. If they report now and then revise in a few months a drop of 50% or more, people will back off in a hurry.