Thank you for your review. The history permission is needed since version 9.0 for better functionality / parity with the legacy add-on. I added a new paragraph to the add-on description:

"New Tab Override needs the permissions to access your tabs and your history. Why does New Tab Override need access to your history? It's needed to prevent spammy "moz-extension://" entries in your browsing history every time you open a new tab. There is no way to prevent this without this permission."