https://www.mozilla.org/en-US/privacy/firefox/
Firefox could then be modified to remove the need to mention "Google", "Microsoft", "DuckDuckGo", "eBay", "our partners", "our third-party ad platform", "a third-party referral platform", "our campaign marketing vendors", "sends Mozilla", and any other companies/organizations/third-parties we find referenced in that document.
A privacy-respecting browser would never collect nor send any data beyond that necessary to provide its core web browsing functionality.
Any functionality that might compromise a user's privacy should not be bundled by default, and would instead have to be explicitly opted into by manually installing an extension that provides such functionality. This would include Firefox's/Mozilla's own "telemetry".