I'm not knowledgable with JS at all, so you're probably right. I do wonder what the "Code Integrity Guard" is going to mean - who has to sign the JS? Does this mean tampermonkey/adblock scripts would stop working? Genuinely asking as like I said I don't really know too much about javascript

This seems to be referring to https://docs.microsoft.com/en-us/microsoft-365/security/defe... which would mean that they require the browser itself to be digitally signed, not the JS.