(At least 'traditionally') an IPO is a cash-raising event, seeking new investment just like any other, so it's not really a secret if a company making a public offering wants cash.

If an IPOd company went immediately bankrupt or otherwise laid off all employees (and presumably ceased operating) the new shareholders would be suing (for securities fraud, it not being clear how at risk the company was, or they wouldn't have invested, etc.) and regulators would probably have serious questions for the bank(s) auditing/DDing/valuing prior to listing.

(IANAL/anything relevant, take your salt, etc.)