@sarina, the text above this batch add box indicates that they do need to have an account and activate it first. looking at staging now, text is:

Batch Beta Testers

Enter email addresses separated by new lines or commas.
Note: Users must have an activated edX account before they can be enrolled as a beta tester. 

This looks like an early draft (ex: missing "Add") but please confirm that the text is completely the opposite of true regarding the requirement to have an activated account.