No, the digital good customers will not need to create a PayPal account. They will, by default, be presented with a credit card payment screen that will allow them to enter their payment info, pay, and download immediately. The screen they will see will be similar to the one shown here:
If you, or your customers, have a cookie on your computer from a previous PayPal use which indicates you are already a PayPal member, then you will see the login screen to make your payment which will also give you the option to pay and download as a guest purchase using another payment method if you don't want to use your PayPal account. This will appear similar to the page shown below:
If you wan to test the non-PayPal flow if you are seeing the above screen, then delete your browser's cookies and restart your web browser and initiate the process again. You should get the first, credit card form, based checkout flow.