Our solution was to comment out the line:
$attendee['holder_name'] = $attendee['purchaser_name'];
in the get_attendees()
method of the Tickets_Order_Helper.php
file. That purchaser_name
field was almost always blank and seems unrelated, so allowing $attendee['holder_name']
to remain at its default ensured that our Attendee Names were making it properly to the email templates.