There were no certificates from the compromised intermediates logged to CT prior to remediation by the browsers.

CT is great for browsers. Largely irrelevant for anything being fetched outside of a browser.

There are plenty of ways you would never be able to tell if a fake cert had been generated and used via this attack vector (let's ignore validation attacks):

1. CT does not do anything if a state actor demands a CA in its borders generate a cert without publishing to the CT logs (or a three-letter-agency doing this illicitly). They can put SCTs in the cert, and still not publish to the logs, nobody is auditing the logs for every cert every browser sees.

2. Browsers won't check for SCTs in certs if they come from a private CA. you can MITM any domain through ZScaler all day long and nobody will notice

3. Wildcard certs make it easy to make/renew a cert that looks normal but hides requests on new/different hosts

4. Non-Browsers do not validate SCTs

Not all TLS traffic involves a browser.

I believe Android updates things like CA certs independently of their monthly security patch. I'm not sure Android 12 uses the same system, but on newer Android I think those are shipped via Google Play system updates, which don't require waiting for the phone vendor.

None of the roots were compromised. (Some of) Their own sub-CAs for TLS certs, which are also cross-signed by Sectigo (since their own roots are rather recent), are affected.

How you have that root cert on your phone with a 3 year old CA set I have no idea, presumably something updated your CAs in the meantime? (Also, aren't you incredibly exposed to the general onslaught of vulnerabilities from the past 3 years?)

To be clear, emSign is another name for EMudhra, and Comodo is now known as Sectigo. (You can't just look at the organization name in a certificate subject; you have to consult the CCADB: https://www.agwa.name/blog/post/the_certificate_issuer_field...)