The latest version of iOS (14.4) is now available as a stable update. Installing it causes a new kind of "important hardware message" to pop up should an iPhone detect that its rear camera module has been unofficially replaced. Apple has also noted that the software includes patches for potentially actionable vulnerabilities.
https://www.notebookcheck.net/iOS-14-4-contains-a-new-anti-independent-repair-message-along-with-security-upgrades.517735.0.html