Hey Christopher,
Welcome to the forums! Sorry to hear you’ve lost some code :-/
To avoid this in the future, I recommend reading our Themer’s Guide. We provide information on how to create custom templates and more importantly, where to keep them so you don’t lose them when updating.
If I understand you correctly, to remove the new tribe-attendees-list-container, you can hide attendee information from being displayed on the front end when adding/editing a ticket on your edit event page (back end). If you want to get a little more gritty with a template override, the file is located at /event-tickets-plus/src/views.

Let me know if I’ve answered your questions and we’ll go from there. Thank you for reaching out and take care!