Not totally following but it sounds like you are saying one of the things they have been doing involves abusing mandated GDPR cookie notices to secretly track people?
IANAL, but it's not GDPR-conformant consent in any way. Consent needs to be informed, unambiguous, and freely given to be valid and should be easy to reject. The only way for this to be valid would be a consent form with something like:
Allow Meta tracking to connect the Facebook or Instagram app on your device to associate visits to this website with your Meta account. Yes/No (With No selected as a default.)
I am pretty sure that this is a grave violation of the GDPR.
Which, on the face of it, sounds like a violation of the GDPR...
>abusing mandated GDPR cookie notices to secretly track people?
How does that even work? What can GDPR cookie notices can do that the typical tracker can't do?
Yes? The cookie in question is First Party, which means you’ve consented to permitting only that party to track you using it, and not permitting its use for wider behavioral tracking across websites.
However, the locally hosted FB/Yandex listener receives all of these first party cookies, from all parties, and the OPs implication is (I think) that now these non-correlateable-by-consent first party cookies can be or are being used to track you across all sites that use them.