This clarification was offered by the administration on Sept 30:

Instead of offering to insure all deposits in money-market funds, it said it would insure only deposits made before the panic broke out on Sept. 19 and it said the insurance would last only for an initial period of three months.

This has subsequently been interpreted to mean your account is insured up to the BALANCE in your account on Sept 19. So this won't help you on newly opened PayPal Money Market Accounts. However, if you have withdrawn funds since then, you can deposit more and it's insured up to the balance you had on the trigger date.