Well, the securities laws require disclosure of material facts. Materiality is with respect to the particular security, which in this case is the notes, not Prosper stock. One could certainly argue that while Prosper's total amount of assets, liabilities, and shareholder equity is material to a note-purchaser, the distribution of equity among the various shareholders is not. So long as the total equity amount is disclosed, why does it matter to a prospective note purchaser how many shares are outstanding, who owns them, or whether previous shareholders got diluted?
These things would be material to a prospective stock purchaser, of course. But a note purchaser?