What are the implications of chrome deprecating third party cookies?

I'm wondering if the following will still be allowed after chrome starts to disallow third party cookies:

• iFrames that load a page from a subdomain or a completely different domain (if they are not in the first prty set - https://github.com/WICG/first-party-sets)

• cookies being sent for http requests to subdomains or completely different domains (if the domains are not in the first prty set)

Based on the above, will technologies like facebook pixel continue to work? If yes, how? If not, then what are workarounds?

Thanks!