Firefox Add-On Source Code

Hi, I am looking at an add-on for Firefox on addons.mozilla.org. It says "This add-on is not actively monitored for security by Mozilla. Make sure you trust it before installing." Under "More Information", it links to a Github page with source code. When "not actively monitored", does Mozilla at least check that the Github page linked to is what is being installed? The add-on is very simple and so I feel confident trusting the code on the Github page, but in clicking "Add to Firefox", I want to make sure that that is indeed the code I am adding. Thanks! Best regards, Nicholas