This blocklist is so extensive, it feels like they just need the phone number of the one person they’re trying to contact

Then this announcement means nothing either way. You can use alternative stores on those phones, still

I was pointing out that switching to Graphene/Lineage doesn’t protect you from the problem being stated in the article as OP implied

Since this is part of Play Integrity API, it’s more likely that this just completely blocks Lineage/Graphene from running these apps too.

It requires your device to be attested as unmodified by Google’s server